Circularly polarized luminescence can directly reveal the chiral characteristics of luminescent systems and provide reliable polarization readouts for applications such as information encryption， anti-counterfeiting， and three-dimensional displays. Recent research has shifted from pursuing signal amplification to emphasizing usability and stability， with progress being made along three pathways： molecular emitters， inorganic hybrid materials， and chiral photonic environments. Focusing on the application of chiral materials， this article first summarizes key factors for achieving large dissymmetry factors from a physicochemical perspective， highlighting predictable emitter design and the regulation of radiative channels through the local environment. It then reviews representative material systems and evidence in scenarios such as multi-level information encryption and patterned anti-counterfeiting， stereoscopic displays and near-eye imaging， enantiomer recognition， and upconverted imaging， comparing the advantages and limitations of different approaches. The article also discusses chemical strategies for maintaining stable signals in complex backgrounds. Finally， in conjunction with the latest measurement standards and data reporting guidelines， practical considerations for standardization are proposed， and future perspectives are outlined toward computation-guided design of high rotatory strength emitters， synergistic control of interfacial interactions and molecular orientation， and chiral transfer across multiple energy levels. These efforts are expected to provide reproducible and generalizable pathways for CPL-based encryption， anti-counterfeiting， stereoscopic vision， and chemical and biological imaging， thereby promoting standardized development in the field.
Contents
1 Introduction
2 The concept of circularly polarized luminescence
3 Construction strategy of circularly polarized luminescent materials
3.1 Chemical synthesis and intrinsic chirality
3.2 Chiral photonic structure
4 Multidimensional applications of circularly polarized luminescent materials
4.1 Information encryption and patterned anti-counterfeiting
4.2 Three-dimensional display and near-eye optics
4.3 Optical sensing and chiral recognition
4.4 CP-OLED
4.5 Spin LED
5 Circularly polarized luminescence metrology and standardization
The iterative development of current information technology is facing a series of key challenges related to "dimensions." In the fields of encryption and anti-counterfeiting, traditional optical information carriers based on intensity or color, due to their inherent static nature and replicability, have become unable to meet increasingly severe security demands[1-2]; in the field of visual display, achieving true stereoscopic display without auxiliary equipment has also progressed slowly due to the lack of efficient polarized light sources[3]. Although these challenges involve different technical levels, their core points to a common scientific bottleneck. We urgently need a new type of photonic material capable of dynamically carrying and directly reading out multi-dimensional information. This material must not only be able to encode complex signals, but the signals themselves should possess an intrinsic, difficult-to-forge uniqueness.
In this context, the interaction between chiral light and matter provides an important pathway to solve the aforementioned problems. Circularly polarized luminescence (CPL) materials can directly encode molecular-scale chiral structural information into the spin angular momentum of emitted photons (left- or right-handed circular polarization)[4-8]. This characteristic makes CPL a natural "information encryption-decryption" platform, where the emission signal itself serves as a dynamic password that is difficult to replicate. Meanwhile, as a light source that directly emits circularly polarized light, CPL also offers a potential physical solution to the bottleneck problems existing in three-dimensional display technology. More profoundly, the extreme sensitivity of CPL signals to their surrounding chiral environment enables them to serve as an intrinsic, non-destructive probe, providing characterization tools for analytical sciences ranging from enantiomer identification to chiral process imaging[9].
However, translating the theoretical potential of CPL into stable and reliable practical technologies still faces numerous challenges. Achieving a high luminescence dissymmetry factor (glum) is fundamental for obtaining strong signal readouts, but more critical is how to achieve precise and predictable regulation of chiral generation, transfer, and emission processes, while ensuring the long-term stability of materials under practical application scenarios[10]. Fortunately, the research paradigm in this field is undergoing a profound shift, moving from the early sole pursuit of maximizing glum values to placing greater emphasis on the usability, stability, and functional integration capabilities of material systems. This shift has demonstrated significant progress across multiple technical pathways, including molecular emitters, inorganic hybrid materials, and the construction of chiral photonic environments[11-13].
Based on this, this article aims to systematically review the latest breakthroughs in circularly polarized luminescence (CPL) materials with an application-oriented approach. The article will first analyze the key design principles for achieving high-performance CPL, starting from physicochemical fundamentals such as excited-state chirality modulation and microenvironmental effects. Subsequently, we will focus on cutting-edge applications including information encryption and dynamic anti-counterfeiting, as well as 3D display and near-eye imaging, while deeply exploring the unique advantages of CPL in analytical fields such as enantiomer recognition and upconversion imaging, providing a horizontal assessment of the performance boundaries and application potential of different material systems. Finally, combining industry trends regarding measurement standardization and data reproducibility, this paper outlines future directions such as computation-driven efficient design, expecting to provide systematic insights to propel CPL technology from the laboratory to practical applications and promote the standardized development of this field.
2 Concept of Circularly Polarized Light
As a transverse wave, the vibration direction of light (the light vector) is perpendicular to its direction of propagation. Natural light consists of a large number of polarized lights with random and irregularly distributed vibration directions; its light vector is uniformly and symmetrically distributed across all spatial orientations perpendicular to the direction of propagation. When the vibration of the light vector is confined to a specific plane, plane-polarized light is produced; since the trajectory of the endpoint of the light vector is a straight line, it is also known as linearly polarized light. When linearly polarized light passes through a quarter-wave plate of a specific wavelength, a phase difference of an integer multiple of π/2 is introduced between its two perpendicular components, causing the trajectory of the light vector's endpoint to change from a straight line to a perfect circle, thereby generating circularly polarized light. Depending on the direction in which the light vector rotates relative to the direction of propagation (clockwise or counter-clockwise when facing the observer), circularly polarized light can be further classified into right-handed circularly polarized light and left-handed circularly polarized light.
To fully and quantitatively describe the polarization state of light, Stokes parameters provide a powerful set of mathematical tools. The Stokes parametersSconsist of four parameters:S = (S0, S1, S2, S3). Among them, S0represents the total intensity of light; S1characterizes the intensity difference of linearly polarized components in the 0° and 90° directions; S2characterizes the intensity difference of linearly polarized components in the ±45° directions; while the key S3directly corresponds to the intensity difference between right-handed and left-handed circularly polarized light (S3 = IR - IL). For completely pure right-handed or left-handed circularly polarized light, its S3value will attain a positive or negative maximum, respectively, while S1 and S2are zero. Stokes parameters can not only precisely describe fully polarized light but also effectively characterize partially polarized or unpolarized light, thereby establishing a unified theoretical foundation for the measurement and analysis of polarization states.
Based on the definition of Stokes parameters, the purity of circularly polarized light is typically quantified by the asymmetry factor (g), which is directly associated with the S3 parameter. The asymmetry factor g for circularly polarized light is defined as twice the ratio of the Stokes parameter S3 to S0, i.e., g = 2 × (S3 / S0). This relationship has clear physical implications: the denominator S0, representing the total intensity, serves for normalization, making the g factor a dimensionless intrinsic property that eliminates the influence of differences in light source intensity; the numerator S3 represents the net dominant direction of circular polarization. Therefore, the g factor essentially quantifies the net relative weight of the circularly polarized component within the total luminescence intensity. Its value range is [-2, +2], where g = +2 indicates pure right-handed circularly polarized light (S3 = S0), g = -2 indicates pure left-handed circularly polarized light (S3 = -S0), while g = 0 implies the disappearance of the circularly polarized component (e.g., unpolarized light or pure linearly polarized light)[14]. Thus, Stokes parameters not only provide a theoretical framework for defining the g factor but also offer a direct pathway for its precise experimental determination. The luminescence asymmetry factor g is defined by Equation (1):
g = 2（IL - IR）/（IL + IR）
in the formula, IL and IR represent the intensities of left-circularly polarized light and right-circularly polarized light, respectively. The g factor ranges between -2 and +2. A larger |g| value indicates higher purity of either the left-circularly or right-circularly polarized light.
Circularly polarized light can not only be obtained by converting linearly polarized light through wave plates but can also be directly generated from the luminescence process of circularly polarized luminescent materials. Understanding from the excited state process of quantum mechanics, the glumessence of this lies in the interaction between the electric dipole transition moment (μgn) and the magnetic dipole transition moment (mgn) during the excited state transition process, as well as their relative orientation (the angle θμm), and its approximate expression is:
glum ≈ 4 × cosθμm × μgn × mgn / [μgn]2
theoretically, if a molecule's transition process satisfies the conditions of "electric dipole transition forbidden, magnetic dipole transition allowed," it is expected to achieve a largeglumvalue. However, the reduction of the electric dipole moment is often accompanied by a decrease in overall luminescence intensity, which necessitates a trade-off between the dissymmetry factor and luminescence efficiency in material design[15].
Therefore, when evaluating the comprehensive performance of circularly polarized luminescence materials (especially in the context of applications such as anti-counterfeiting and information security), one cannot merely pursue a highglumvalue; the total photon output must also be considered. To this end, researchers have introduced circularly polarized luminescence brightness (BCPL) as a comprehensive evaluation metric, which can be defined by Equation (3):
BCPL = ελ × Ф × |glum| / 2 = B × |glum| / 2
among them, ελis the molar extinction coefficient, Фis the fluorescence quantum yield, Bis the traditional fluorescence brightness. This definition combines the material's absorption capacity (ελ), emission efficiency (Ф), and polarization characteristics (glum) to provide a more reliable basis for comprehensively evaluating the performance of materials in practical applications[16].
3 Construction Strategies for Circularly Polarized Luminescent Materials
3.1 Chemical Synthesis and Intrinsic Chirality
By directly constructing chirality into the skeleton of luminescent molecules via chemical synthesis, excited-state chirality can be generated at the molecular scale through coherent coupling of electric and magnetic dipole transitions, thereby achieving stable circularly polarized luminescence signals. Chemical synthesis provides tunable parameters for this "structure-to-readout" causal chain, including the type and position of chiral elements, the rigidity and coupling modes of the π-skeleton, the introduction of heavy atoms and spin-orbit effects, as well as the synergy between coordination fields and ligand sensitization. So-called intrinsic chirality refers to chirality originating from the asymmetry of the molecule's own spatial structure, rather than being induced or formed by external environments or assembly. Such chirality is typically determined by the inherent arrangement of chiral centers or chiral axes within the molecule, thus possessing definite configurational relationships and stable optical rotation characteristics. Intrinsic chirality unifies tunable configuration, energy levels, and rigidity within the molecular framework, facilitating the consistent expression of helical information across solutions, aggregated states, and thin films.
3.1.1 Chiral organic compounds
The design strategy for chiral organic small-molecule CPL materials is shifting from simple grafting of chiral groups toward inducing intrinsic chiral distortion in the π-conjugated backbone, achieving coupling between the chiral source and the luminescent center at the electronic orbital level, thereby synergistically enhancingglumandΦPL[17].As shown in Fig. 1a, b, the team of Wang and Jiang[18]explored the laws of chiral transfer and amplification through precise molecular synthesis. They constructed covalent double π-helical nanoribbons based on perylene diimide (PDI). The study found that in linear oligomers composed of homochiral units (from dimers to tetramers), the CPLglumincreased linearly from 0.007 to 0.015, achieving stepwise amplification of the chiral signal. More importantly, this series of materials simultaneously maintained an extremely high fluorescence quantum yield of 83%~95%, enabling their circularly polarized luminescence brightness (BCPL) to reach 575 M⁻1·cm⁻1, an excellent level. This work provides an ideal model system for understanding the mechanisms of chiral generation, transfer, and amplification at the molecular level.
Asshown in Figures 1c and d, a highly stereoselective synthetic method has achieved the scalable preparation of chiral adjacent bridged carboranes[19]. The study reveals that the unique three-dimensional aromaticity, large steric hindrance, and electron-deficient characteristics of carboranes can synergistically enhance the luminescent performance of materials. Compared with analogues without carboranes, this chiral carborane derivative not only increases theΦPLby 30%, but also significantly enhances itsglumby 9-fold. This "win-win" strategy demonstrates the great potential of utilizing specific building blocks to simultaneously optimize luminescence efficiency and chiroptical activity.
While significant progress has been made in CPL materials in the visible region, developing circularly polarized luminescent materials with emission wavelengths in the biological tissue "transparent window" (near-infrared region, NIR) is of crucial importance for advancing the application of CPL in biomedical fields such as in vivo imaging and deep tissue detection.[20]. However, achieving efficient near-infrared circularly polarized phosphorescence (NIR-CPP) faces huge challenges due to the inherent energy gap law.[21]. In this direction, Tang et al.[22]achieved a key breakthrough. They designed and synthesized chiral enantiomers based on highly twisted helical ring-locked heteroaromatics.R-/S-BBTI (Fig. 2a, b). Their core strategy lies in introducing iodine heavy atoms to enhance spin-orbit coupling and constructing a rigid spirocyclic structure to suppress non-radiative transitions. The molecule exhibits a phosphorescence dissymmetry factor as high as 0.013 and a phosphorescence quantum efficiency of 4.2% in solution, with a phosphorescence lifetime reaching 119 μs (Fig. 2c). Mechanistic studies indicate that the synergy of lone pair n-orbital participation, intramolecular charge transfer characteristics, and the heavy atom effect effectively promotes intersystem crossing, thereby achieving efficient NIR-CPP emission. The phosphorescence of this material is oxygen-sensitive and has been successfully applied to hypoxia imaging in biological systems, providing a paradigm for the practical application of NIR-CPP materials.
3.1.2 Chiral inorganic compounds
The aforementioned chiral organic small molecules, based on precise molecular engineering, demonstrate exceptional potential in revealing chirality-luminescence coupling mechanisms and achieving high-performance CPL through ingenious molecular design, particularly exhibiting unique advantages in solution processability and molecular structure regulation.[23]However, when application targets shift to scenarios demanding extreme durability, such as long-term anti-counterfeiting, sensing in harsh chemical environments, or micro-optoelectronic devices operating under intense light irradiation, the structural stability and fatigue resistance of materials become critical considerations. In this context, chiral inorganic compounds, owing to their superior chemical, thermal, and photostability conferred by rigid lattices, provide an important complementary pathway for developing long-lasting and reliable CPL materials, functionally complementing organic systems.[24].
In the exploration of constructing intrinsically chiral inorganic luminescent materials, researchers have developed various strategies to achieve effective transfer and solidification of chirality from the molecular scale to the inorganic lattice. Tao et al.[25]'s groundbreaking work, asshown in Figure 3a, by introducing chiral organic cations (such asR-/S-MBA⁺) into the lattice of three-dimensional lead halide perovskites, successfully induced a cooperative distortion of the inorganic [PbI6]4⁻ octahedral framework, forming intrinsically chiral perovskite single crystals. This structural chirality is not only reflected in strong circular dichroism (CD) signals but also transferred to their luminescence process, generating significant CPL signals (|glum|~10-2) (Figure 3b). This work demonstrates that through chirality engineering at the lattice level, effective transfer of chirality from organic components to inorganic components can be achieved, providing a new paradigm for developing chiral inorganic luminescent materials with high stability. Unlike the aforementioned strategy of introducing chirality into existing lattices, another path focuses on directly constructing chiral structures during the nucleation and growth of nanocrystals.Figure 3cdepicts a class of purely inorganic rare-earth phosphate nanowires with atomic-level chirality, achieving multicolor, highly stable circularly polarized luminescence[26]. Unlike traditional CPL materials that rely on organic chiral templates or surface ligands, the chirality of this material originates from the chiral spatial structure of the crystal itself (such asP6222), synthesized via chiral molecule-induced symmetry breaking, exhibiting excellent enantioselectivity. By doping with different rare-earth ions (Eu3⁺, Tb3⁺, Tm3⁺), the CPL emission color can be tuned, and luminescence stability can be maintained at high temperatures up to 300 °C. Furthermore, these nanowires can be dispersed in polymers to prepare transparent and flexible CPL films, expanding their application prospects in chiral optoelectronic devices and providing new ideas for developing inorganic materials with stable chirality and tunable CPL.
To further enhance chiroptical performance, Long et al.[27]designed and synthesized chiral europium-based halides (R/S-3BrMBA)3EuCl6. This material combines the narrow-band red emission (594 nm) from Eu3⁺ ion f-f transitions, high photoluminescence quantum yield (ΦPL = 59.8%), and long lifetime (~2 ms) characteristics (Fig. 4a). Notably, this study achieved, for the first time, effective modulation of the photoluminescence polarization degree of chiral europium-based halides via an external magnetic field, observing an anomalous positive magneto-photoluminescence effect at room temperature (Fig. 4b). This provides new insights for developing novel magneto-optical multifunctional CPL materials. Continuing the exploration of chiral amplification mechanisms, the team also constructed zero-dimensional (0D), one-dimensional (1D), to three-dimensional (3D) indium(III)-based chiral halides through a cascaded cation insertion strategy[28](Fig. 4c). As the structural dimensionality of the materials increases, their |glum| increases exponentially from the order of 10⁻³ to nearly 0.09, while maintaining high ΦPL(up to 89.42%) (Fig. 4d). The study indicates that the increase in material structural dimensionality promotes the formation of helical structures and more efficient chirality transfer from organic components to inorganic components; in particular, the significant increase in mgn is the fundamental reason for the enhancement of glum.
Although chiral inorganic CPL materials exhibit stability including excellent heat resistance, bleaching resistance, and chemical inertness, making them highly suitable for devices requiring long-term use or operating in harsh environments, and their inherent rigid lattices also facilitate the long-term retention of chiral signals. However, such materials typically face challenges that constrain their development, including stringent synthesis conditions (such as high temperature, absence of water and oxygen), insufficient flexibility in designable molecular structures, and generally poor biocompatibility.
3.1.3 Chiral metal complexes
From structurally precise and controllable chiral organic small molecules to chiral inorganic compounds with excellent stability, research has demonstrated effective strategies for constructing CPL materials across different scales. However, in the pursuit of combining molecular-level designability with the unique photophysical properties of metal centers (such as phosphorescence induced by strong spin-orbit coupling, f-f transitions of lanthanide ions, long-lived luminescence, etc.), chiral metal complexes undoubtedly occupy a central position.[29-30]. Such materials tightly integrate the chiral environment of organic ligands with metal ions through coordination bonds, providing a key pathway for achieving precise regulation and functional integration of chiral luminescent properties at the molecular level.[31].
In the research of circularly polarized luminescent metal complexes, achieving performance breakthroughs and functional innovations is the core challenge. Sun et al.[32]through exquisite supramolecular design, asFigure 5ashows, utilized chiral ligands and Ln3⁺ ions (such as Yb3⁺, Er3⁺) to self-assemble into chiral tetrahedral cages with defined structures. Under 980 nm near-infrared light excitation, through Yb3⁺-sensitized Er3⁺ synergistic upconversion energy transfer, a significant CPL signal was finally observed in the characteristic emission band of Er3⁺ (~650 nm) (glum 10-2) (Figure 5b). This is the first instance of UCCPL achieved in discrete rare-earth supramolecular systems, demonstrating the unique ability of metal complexes to expand the application wavelength range of CPL. In the pursuit of high-performance CPL materials, the work of Zhong et al.[33]demonstrates the important role of molecular assembly. They designed N^N^C-coordinated platinum complexes with chiral substituents (Figure 5c), and by regulating the molecular packing mode, successfully prepared highly efficient circularly polarized phosphorescent films with chirality inversion starting from the same chiral molecule. Notably, the film simultaneously achieved a phosphorescence quantum yield of >50% and a high |glum| > 0.5 synergistic optimization (Figure 5d). Theoretical analysis indicates that planar platinum complexes, through multi-level chiral assembly, form an interpenetrating fibrous network crystalline structure; this long-range ordered chiral superstructure is key to obtaining giant asymmetry factors. Based on this property, the material has been successfully used as a chiral filter to induce circularly polarized light from achiral luminescent molecules. Furthermore, the application of chiral metal complexes in the field of intelligent sensing also shows broad prospects. The dynamic chiral europium complexes developed by Liang and Zou et al.[34]exemplify the development in this direction. This chiral EuFigure 6a) emitter possesses both a high |3⁺ complex with high |glum| ~ 0.64 andBCPL~2429 M⁻1·cm⁻1(Figure 6b). More importantly, in the aggregated state, the complex exhibits high selectivity and chiroptical response towards extremely low concentrations of Cu2⁺ ions, with a detection limit as low as 2.55 nM (Figure 6c); this work provides important references for the practical application of chiral CPL materials in environmental monitoring and other fields.
The aforementioned chiral metal complex CPL materials can not only undergo flexible molecular tailoring via organic ligands but also utilize metal centers to introduce unique physical properties such as phosphorescence, long-lived luminescence, and upconversion luminescence, thereby achieving integrated performance design. However, the stability of some complexes in solution or solid state, particularly their photostability, still needs improvement.
The above results discuss the research progress in constructing intrinsic chiral luminescent materials within three major systems: organic compounds, inorganic compounds, and metal complexes, via chemical synthesis strategies. These works demonstrate that through rational molecular design and synthesis strategies, the chiroptical properties of materials can be effectively regulated across different scales. In the system of chiral organic compounds, strategies such as constructing helical π-conjugated backbones, regulating substituent electronic effects, and engineering aggregation states are primarily employed to achieve precise optimization of the luminescence dissymmetry factor. Chiral inorganic compounds utilize methods like chiral template-induced lattice distortion, crystal dimensionality regulation, and defect engineering to construct stable chiral luminescent centers within rigid structures. Chiral metal complexes leverage approaches including coordination geometry regulation, ligand field engineering, and supramolecular assembly to achieve multi-level modulation of chiral luminescent performance. These specific synthesis strategies provide a clear technical blueprint for the rational design of materials with specific chiroptical properties, showcasing the powerful capability of chemical synthesis in the precise construction of functional chiral materials.
3.2 Chiral photonic structures
Beyond directly constructing intrinsically chiral luminescent materials via chemical synthesis strategies, utilizing chiral photonic structures to regulate light-matter interactions represents another important pathway for achieving CPL[4]. The core of such strategies lies in the meticulous design of the spatial periodic arrangement of the material's dielectric constant to form a chiral photonic environment, thereby non-covalently modulating the radiation processes of emitters embedded within it[35]. Unlike molecular intrinsic chirality, which relies on quantum interference between electric and magnetic dipole transitions, chiral photonic structures primarily employ physical mechanisms such as photonic bandgap effects, chiral mode field localization and enhancement, and optical activity to selectively amplify the emission rate of specific chiral modes or suppress their opposite counterparts, ultimately generating significant CPL output at the macroscopic level. The greatest advantage of this method lies in its universality; even non-chiral classical emitters can produce strong CPL signals once placed within suitable chiral photonic structures[36]. This section will focus on four representative types of chiral photonic structures—cholesteric liquid crystals, chiral polymers, chiral elastomers, and liquid crystal microcapsules—systematically elucidating their structural design principles, CPL regulation mechanisms, and significant progress in recent years.
3.2.1 Cholesteric liquid crystal
Cholesteric liquid crystals form quasi-one-dimensional helical superstructures through molecular self-assembly. Their unique photonic bandgaps and optical activity provide an ideal physical platform for CPL modulation, making them one of the most extensively studied chiral photonic structure platforms.[37]. The core advantage of such materials lies in their ability to achieve precise control over the position of the photonic bandgap and the direction of chirality by adjusting the content of chiral molecules and applying external fields, thereby providing a chiral environment for luminescent materials embedded within them. In recent years, researchers have continuously expanded the application boundaries of cholesteric liquid crystals in the field of CPL through ingenious material design and structural regulation.
Asshown in Figure 7a, Duan et al.[38]designed a composite system based on cholesteric liquid crystals and upconversion/downshifting luminescent materials. This work constructed a "superstructural helix," ingeniously integrating chiral photophysical processes with macroscopic photonic structures. Through carefully designed energy transfer pathways (triplet-triplet annihilation photon upconversion), synergy was generated between the upconversion annihilator and the downshifting sensitizer, thereby achieving "killing three birds with one stone" within a single system, namely three types of circularly polarized emission under one excitation. Furthermore, leveraging the chiral amplification mechanism of the helical superstructure, molecular chirality was enhanced via the triplet-triplet annihilation process and subsequently further amplified by the long-range order of the liquid crystal, ultimately reaching an asymmetry factor of 0.68 (Figure 7b). This study reveals the universal regulatory capability of supramolecular helical structures over multiple luminescence mechanisms. Additionally, Lu et al.[39]proposed an optical multi-dimensional patterning technology based on programmable UV polarization and dosage, designing a heterogeneous liquid crystal superstructure composed of interlocked nematic and chiral liquid crystals (Figure 7c). By precisely controlling the transverse and longitudinal arrangement of liquid crystal molecules using this technology, they achieved multi-dimensional manipulation of light within a single-layer micrometer-thick film. This superstructure not only synchronously realizes brightness-tunable, polarization-selective near-field full-color printing and far-field full-color holography but also achieves high information density storage of approximately 1.6 million mixed-dimension optical data per mm2 at low cost, thereby opening new avenues for applications such as high-order information optical storage, dynamic display, and multi-dimensional encryption, and pioneering a new paradigm for full-dimension optical research mediated by soft matter.
3.2.2 Chiral polymers
As the core carrier of a new generation of optical functional materials, chiral polymers exhibit significant advantages in the field of circularly polarized optics due to their programmable helical conformations and anisotropic optoelectronic response characteristics[40-41]. These materials not only achieve efficient generation and amplification of circularly polarized light through molecular-level chirality transfer and symmetry breaking during supramolecular assembly, but also possess the capability for synergistic regulation of multi-dimensional optical parameters[42-43]. In recent years, with the integrated development of inverse design and high-throughput experimental methods, researchers have been able to overcome the limitations of traditional "trial-and-error" approaches, achieving precise customization of material optical properties within complex multi-dimensional parameter spaces, thereby opening new pathways for the application of chiral polymers in cutting-edge optoelectronic fields[44].
Zou et al.[45]broke through the limitations of traditional material development by achieving inverse design of chiral polymer films through an artificial intelligence system (Fig. 8a, b). This system can autonomously screen and optimize from over hundreds of millions of possible structural parameter combinations to fabricate functional films with customizable and ultra-high dissymmetry factors (gabs ~ 1.9) across the entire visible light spectrum. This study not only demonstrates the practical value of the materials in circularly polarized selective filtering and switchable luminescence but also pioneers a research paradigm combining AI-driven high-throughput experiments with machine learning-based inverse design, significantly advancing the process of customized applications of chiral polymers in frontier fields such as information encryption, 3D displays, and quantum communication. Meanwhile, Duan et al.[46]composite chiral soft photonic crystal films as the host matrix with upconversion luminescent systems to construct colorful flexible upconversion circularly polarized luminescent films featuring both high dissymmetry factors and excellent stability (Fig. 8c, d). In this system, the chiral soft photonic crystal films not only provide a strong chiral microenvironment for the luminophores, significantly enhancing the luminescence dissymmetry factor, but also achieve stable protection of the luminescent centers through the dense structure formed by co-assembly with polymers, enabling the material to maintain long-term performance stability in air and common solvents. This innovative design perfectly combines the color tunability of upconversion luminescence with circular polarization characteristics, realizing multi-dimensional optical control of excitation wavelength, emission color, and polarization state.
3.2.3 Chiral elastomer
Chiral elastomers ingeniously integrate microscopic chiral periodicity with macroscopic network elasticity, demonstrating unique functional integration characteristics under multi-physics coupling. Through the synergistic mechanism of chiral arrangement and network deformation, they achieve mutual regulation between optical properties and mechanical deformation. This bidirectional light-mechanical modulation transcends the response limitations of traditional functional materials, establishing a dynamic mapping relationship between optical signals and mechanical deformation, thereby opening new technological pathways for frontier fields such as flexible photonic devices, adaptive camouflage systems, and soft robots.[47].
Xie et al.[48]synthesized luminescent liquid crystal elastomers via a one-pot method. Based on the fluorescence resonance energy transfer mechanism, they constructed smart waveguide fibers with extremely low optical loss and excellent mechanical properties (Fig. 9a, b). This material can undergo reversible macroscopic deformation under thermal or light stimulation, thereby achieving dynamic control over light propagation paths and demonstrating the function of active optical signal modulation in flexible photonic circuits. Building on this, Feng et al.[49]further expanded the application scenarios of chiral materials. They designed a chiral liquid crystal ink with good printability, which, combined with an evaporation-induced self-assembly process, enables the rapid construction of high-resolution structural color patterns on various rigid and stretchable substrates (Fig. 9c, d). The prepared patterns not only possess circularly polarized optical properties but also exhibit reversible color changes in response to strain. Especially when integrated into electronic textiles, they enable synchronized responses and multiple feedback among mechanical deformation, optical color, and electrical capacitance, providing a novel sensing interface for dynamic human-machine interaction in smart wearables and soft robotics. These two studies highlight the significant value and application prospects of chiral elastomers as intelligent soft matter materials in next-generation integrated flexible systems, from the perspectives of "internal optical path regulation" and "external information display and control," respectively.
3.2.4 Liquid crystal microcapsules
Liquid crystal microcapsule technology achieves stable encapsulation and performance optimization of functional materials through a core-shell structure. Its unique confined space provides an ordered assembly microenvironment for optically active molecules, significantly enhancing the material's environmental resistance and mechanical stability.[50]. This encapsulation strategy not only resolves the technical bottlenecks of traditional liquid crystal materials in processing applications but also, through precise interface regulation, enables the material to retain its intrinsic optical activity while acquiring diverse processing characteristics such as sprayability and weavability.[51].
Asshown in Figure 10a, Guo et al.[52]developed a light-regulated liquid crystal microcapsule system. By constructing a fluorescence resonance energy transfer platform between chiral donors and achiral molecular switches within cholesteric liquid crystals, they achieved full-color dynamic circularly polarized luminescence (CPL) tuning from blue to red induced by UV light. The unique advantage of this system lies in the significant time-dependence of its emission color and CPL signal intensity, thereby enabling the construction of a "four-dimensional" information encryption system that integrates emission color, polarization state, and specific irradiation time. Regarding thermally responsive systems, Tang et al.[53]designed intelligent microcapsules based on phase change materials, doping chiral AIE molecules into an alkane phase change matrix to achieve reversible CPL regulation via solid-liquid phase transitions (Figure 10b). Under solid-state conditions, the aggregation of AIE molecules generates strong CPL signals; when the temperature rises above the phase transition point, the material melts into a liquid state, causing CPL signal quenching and a shift in emission color. This CPL switching effect, dependent on changes in physical state, introduces a temperature-responsive mechanism, requiring information decryption to simultaneously satisfy both specific temperature conditions and CPL detection. These stimulus-responsive systems based on microcapsule structures demonstrate significant advantages in constructing multi-dimensional encryption logic by generating precise optical responses to external stimuli such as light and heat (Figure 10c).
4 Multidimensional Applications of Circularly Polarized Luminescence Materials
Circularly polarized luminescent materials, due to their unique optical properties, are promising in intelligent sensing[54], 3D displays[55], logic gates[56], catalysis[57], and anti-counterfeiting encryption[4]and other fields. Regardless of the application area, achieving a high luminescence dissymmetry factor is always the primary requirement. Circularly polarized materials with high dissymmetry factors offer two typical advantages: (1) they can improve detection sensitivity by avoiding interference from other optical signals; (2) they can increase detection channels, allowing not only detection using expensive equipment but also naked-eye differentiation assisted by left- and right-circular polarizers.
4.1 Information Encryption and Pattern-based Anti-counterfeiting
Recently, Liu et al.[58]successfully constructed a supramolecular polymer system by coordinating and assembling Z-type molecules with wavelength-dependent photoresponses with silver ions. Under 454 nm irradiation, reversible inversion of the CPL chiral sign and switching of the emission color from yellow-green to orange-yellow were achieved. Furthermore, under 365 nm irradiation, the emission was tuned to the blue region via a photocyclization reaction (Fig. 11a, b). Through the synergistic mechanism of "molecular isomerization-supramolecular reorganization," this work not only demonstrates multidimensional optical output via light programming but also combines dynamic CPL with multiple decryption modes to construct an information encryption system with high security (Fig. 11c). While achieving dynamic regulation of CPL, enhancing its |glum| value has always been one of the core goals pursued in this field. Liu, Ouyang, et al.[59]proposed a novel "non-covalent-covalent synergy" strategy. By doping anthraquinone (AQ) molecules into the nematic liquid crystal SLC1717 and introducing a chiral inducer, an in situ photo-addition reaction between AQ and the diarylacetylene component in the liquid crystal occurred under UV irradiation, thereby covalently anchoring the chromophores within the chiral liquid crystal network. This strategy enabled the resulting material to achieve a glum value as high as 1.73, approaching the theoretical limit. Its outstanding performance stems from the high structural similarity between the in situ generated emitters and the liquid crystal components, thus achieving perfect orientation and signal amplification of the chromophores while maintaining the original helical structure. This system was further utilized to construct circularly polarized luminescence patterns with high contrast and a Morse code-based multiple information encryption system (Fig. 11d).
Building upon the breakthrough of moving beyond simple superposition of structural color and fluorescence/phosphorescence to achieve dynamic multi-mode anti-counterfeiting, researchers have begun to address the challenge of mutual interference between multiple optical signals. As Chen, Zou, et al.[60]recently demonstrated, they successfully constructed a dynamic multimodal encryption system featuring programmable structural color and switchable CPL, achieving orthogonal regulation of different optical channels for the first time (Figure 12a). The upper layer of this system consists of a polydiacetylene microarray with a programmable periodic structure, enabling dynamic switching of structural color via incident light angle or solvent stimulation. The lower layer employs twisted stacked silver nanowires as optical converters, transforming the fluorescence of perovskite nanocrystals into high-glum(reaching 1.3) strong CPL signals. Crucially, by precisely controlling the aspect ratio of the upper microstructures, the structural color and the lower fluorescence/CPL signals can not only be independently modulated without interference but also selectively "hidden" or "exposed," thereby realizing a leap from "static multi-mode display" to "dynamic programmable encryption."
Building upon the successful realization of dynamic multimodal information encryption and independent regulation in the visible region, the research further advances toward higher levels of concealment and security. Recently, Duan et al.[61]By combining NIR-CPL with the concept of Physical Unclonable Functions (PUFs), they have elevated the complexity and security of information encryption technology to a new height (Figure 12b). This study designed a composite material based on chiral imprinted photonics films (CIP) and ytterbium (Yb³⁺)-doped perovskite nanocrystals (PeNCs). Its innovation lies in the fact that after removing the liquid crystal component, the CIP film perfectly retains its chiral nanocavities and photonic bandgap, achieving not only a |glum| value as high as 0.9, but more critically, the random structural disorder introduced during its preparation, combined with the random distribution of Yb-PeNCs within the cavities, jointly constitutes an uncopyable physical entropy source. The resulting NIR-CPL signal, due to its invisibility to the human eye and unique chiral information, serves as an extremely covert encryption carrier. Through image processing techniques, researchers converted the random responses of different samples across multiple optical channels, including NIR, CPL intensity, and glum values, into high-capacity binary keys, thereby constructing an optical PUF system based on NIR-CPL. This work effectively advances chiral optical materials into the practical application stage of "leveraging intrinsic randomness to create physically unclonable functions," providing a novel solution that combines high concealment, high encoding capacity, and physical unclonability to address increasingly severe challenges of advanced counterfeiting.
4.2 3D Display and Near-Eye Optics
While information encryption and anti-counterfeiting technologies continue to evolve towards multi-dimensionality and dynamism, these advanced optical modulation strategies have also injected new vitality into the fields of 3D display and near-eye optics. In particular, materials based on self-assembled 3D photonic structures exhibit immense application potential due to their pixel-level optical anisotropy and dynamic tunability. Wang et al.[62]based on blue phase liquid crystal 3D photonic crystals, achieved spatiotemporal programming of microscopic 3D chiral color units by driving asymmetric lattice deformation through spontaneous ink diffusion (Figure 13a). This work extends the research focus of dynamic optical modulation from 2D planes to 3D space, achieving continuous regulation of photonic bandgap structures by precisely controlling the diffusion gradient of ink along the film thickness direction. Notably, the double-helix polymer network designed by the researchers integrates structural layers with opposite chirality (one up, one down) within a single device, enabling the reading of image information from different depths at the same spatial location simply by switching circular polarizers. This opens a new path for developing multiplexing technologies in glasses-free 3D displays and near-eye displays (Figure 13b). Combined with its demonstrated angle-dependent iridescent effects and machine learning-assisted programmability, this system showcases broad application prospects for 3D photonic materials in next-generation spatial light modulators, holographic displays, and near-eye optical systems such as augmented reality. With the coordinated development of information encryption, anti-counterfeiting, and 3D display technologies, the demand for novel bionic visual devices capable of perceiving and processing these complex optical signals is becoming increasingly urgent. In exploring frontier material systems that can intelligently respond to circularly polarized light, a retina-like device based on photo-ionic cholesteric liquid crystals ingeniously integrates a chiral polymer network for precise identification of left- and right-handed circularly polarized light with an ionic polymer network providing high capacitance (up to 580 nF·cm⁻²), thereby achieving "sensing-computing integration" at the material level.[63]. By integrating this film as a dielectric layer into an organic field-effect transistor, the constructed detector not only achieves a record-high asymmetry factor (gph=1.33), but also operates at voltages below 5 V, with its detection range covering the entire visible spectrum. Based on these exceptional performances, this study further demonstrates its wide applications in multimodal neuromorphic visual systems, ranging from mantis shrimp-inspired target recognition and optical communication with logical computing capabilities to high-security 4D data encryption. Especially in tasks involving the differentiation between circularly polarized and ordinary light information, the system achieved an accuracy of 75.73% (Figure 13c).
Following progress in functional materials for three-dimensional photonic structure regulation, Zhuang et al.[64]successfully prepared solid-state CPL-active photonic coatings with a core-shell structure by employing a confined helical co-assembly strategy, overcoming the technical bottlenecks of traditional chiral liquid crystals in flexible processing. Notably, the resulting materials not only achieved a high luminescence dissymmetry factor of 1.6 and long-term stability exceeding 80 days, but also demonstrated excellent printability, enabling the fabrication of fine patterns and meter-scale coatings on various flexible substrates (Figure 13d). Based on this breakthrough, the research team constructed a complete flexible stereoscopic display system on a fabric substrate by alternately printing left- and right-handed luminescent pixel arrays, demonstrating its application prospects in wearable devices.
4.3 Optical Sensing and Chiral Recognition
In the fields of optical sensing and chiral recognition, circularly polarized room-temperature phosphorescent materials exhibit broad application prospects due to their unique chiroptical properties and long-lived luminescence performance. Zhang et al.[65]successfully constructed a series of full-color-tunable circularly polarized room-temperature phosphorescent materials by compositing anionic cellulose derivatives (such as CBtCOONa and CMCNa) with achiral luminescent molecules (Figure 14a). This material system utilizes the helical structures spontaneously formed by cellulose derivatives under electrostatic repulsion to transfer chirality to the luminescent molecules. Through interactions such as hydrogen bonding, electrostatic forces, and π-π stacking, non-radiative transitions are suppressed, thereby achieving efficient circularly polarized phosphorescence emission. The prepared materials not only possess excellent processability, allowing them to be fabricated into large-area films and flexible three-dimensional objects, but also exhibit excitation wavelength dependence, time dependence, visible light excitation, and multiple responsive characteristics to external environments (humidity, temperature, pH). Notably, these materials enable the visual identification of various chiral enantiomers (such as amino acids, hydroxy acids, organophosphates, and benzoin, etc.) through naked-eye-visible changes in phosphorescence color without the need for instrumental assistance, demonstrating their immense potential in chiral sensing and intelligent recognition (Figure 14b). Furthermore, based on natural cellulose, this material system combines the advantages of biodegradability, biocompatibility, and ease of scalable preparation, providing new insights for the development of green and efficient chiroptical sensing materials.
Chiral optical materials are not only applicable for static recognition but also demonstrate immense potential in dynamic, real-time stereoscopic vision and interactive systems. Zhuang, Yu, et al.[66]developed a flexible spatial display panel based on self-aligned multilayer circularly polarized electroluminescent microdevices. By integrating chiral liquid crystal microspheres with synergistic polarization and electroluminescent layers, the device achieves a luminescence asymmetry factor as high as 1.0 under electric field driving, capable of generating high-quality left- and right-handed circularly polarized light output (Figure 14e). This display system, through alternating arrangement of left- and right-handed pixels coordinated with smart polarized glasses, simulates human binocular stereoscopic vision to generate three-dimensional images with depth information in real time, thereby enabling immersive human-machine interaction in extended reality environments (Figure 14c). The researchers further applied this system to remote robot manipulation and simulated rescue scenarios, verifying its reliability in real-time depth perception and virtual-reality interaction (Figure 14d).
In the field of circularly polarized luminescence devices, achieving high-performance white circularly polarized electroluminescence has always been a key challenge urgently awaiting a breakthrough.[67]. In recent years, an innovative "orthogonal engineering" strategy has provided new ideas for resolving the inherent contradiction between efficiency and polarization degree.[68](Figure 15a). This scheme successfully achieved a performance breakthrough through a clever stacked design combining non-chiral blue TADF materials with chiral orange assemblies. In this architecture, the upper chiral assembly exhibits dual functions: it can selectively absorb blue light of specific polarization directions and excite strongly polarized orange light, while efficiently transmitting blue light of orthogonal polarization directions. This unique working mechanism enables the final output white light to possess both high external quantum efficiency (EQE up to 14.7%) and a record-breaking electroluminescence dissymmetry factor (|gEL| reaching 0.34) (Figure 15b). The significant importance of this study lies in successfully breaking the mutual constraint between efficiency and polarization degree for the first time through the design concept of functional separation, opening a new technical path for developing next-generation circularly polarized luminescence devices. Following the success of the "orthogonal engineering" strategy in enhancing the performance of white circularly polarized organic light-emitting diodes (CP-OLEDs), Cheng et al.[69]further proposed a programmable circularly polarized electroluminescence strategy based on stereochemical regulation (Figure 15c). This study selected AIE-active chiral inducers with different dihedral angle structures (S-/R-1 and S-/R-2) to co-assemble with the non-chiral liquid crystal polymer PyP, constructing an emissive layer with a highly ordered structure. The study found that as the dihedral angle of the binaphthyl group changed from obtuse to acute, the co-assembled film not only achieved a reversal of the circularly polarized luminescence signal after thermal annealing but also significantly enhanced its dissymmetry factor. The optimal device (S-/R-2)0.1-(PyP)0.9emitted blue light at 480 nm, reached a maximum brightness of 14,860 cd/m², and set a record for the highest |gEL| value (0.18) based on chiral co-assembly systems (Figure 15d). This work achieved, for the first time, the regulation of the direction and intensity of CP-EL signals through chiral molecular configuration control, providing new ideas for developing dynamically tunable circularly polarized luminescence devices.
4.5 Spin Light-Emitting Diode
In the field of circularly polarized luminescence devices, various breakthrough strategies have emerged in recent years[70], which not only significantly improve the device'sgELand EQE, but also achieve synergistic regulation of multiple degrees of freedom such as light, electricity, and spin at the physical mechanism level, demonstrating strong interdisciplinary characteristics. Following molecular-level strategies such as "orthogonal engineering" and "stereochemical control," researchers have further expanded the performance boundaries of CP-OLEDs from the perspectives of spin injection and band engineering. Kim et al.[71]utilized the chiral-induced spin selectivity effect to realize spin-polarized light-emitting diodes without external magnetic fields or ferromagnetic contacts at room temperature (Figure 16a). By embedding chiral organic molecules into a two-dimensional metal halide perovskite framework to construct a chiral-induced spin selectivity (CISS) layer, they achieved a spin polarization rate of up to 80% during hole injection, thereby realizing circularly polarized electroluminescence in the CsPbBr₃ nanocrystal emitting layer with a polarization degree of 2.6%, verifying for the first time at room temperature a pure electrically controlled spin luminescence mechanism based on CISS (Figure 16b). Meanwhile, Friend et al.[72]proposed a novel chiral supramolecular semiconductor film strategy from the perspective of energy bands. By preparing TAT molecular assemblies with a helical stacking structure via vacuum co-evaporation, theoretical calculations indicated significant angular momentum splitting in their conduction and valence bands, thereby directly generating highly polarized photons during the electroluminescence process (Figure 16c). While achieving agEL ~ 0.1, the device maintained an EQE as high as 16%, breaking the traditional trade-off between efficiency and polarization degree (Figure 16d). These two works advanced the development of CP-OLEDs from two physical aspects: "spin filtering" and "band angular momentum control." The former introduced spintronic mechanisms into light-emitting devices to achieve room-temperature spin luminescence, while the latter directly generated circularly polarized light through band engineering of chiral superstructures without requiring strong spin-orbit coupling. These studies not only expanded the material systems and device structures of circularly polarized luminescence devices but also profoundly revealed the intrinsic connections among chiral structures, band topology, and spin transport, laying a solid foundation for developing high-performance polarized light sources and spin-optoelectronic devices based on quantum control.
5 Circularly Polarized Luminescence Metrology and Standardization
Against the backdrop of the rapid development of chiral photonic materials, the reliability and comparability of measurement data have become a key bottleneck constraining the healthy growth of this field. Lu, Di Bari, and Favereau[73]addressed this core challenge by systematically proposing, for the first time, a standardized framework for circularly polarized luminescence (CPL) characterization. This work transcends the mere demonstration of high-performance materials, shifting the focus to the foundation supporting the development of materials science: reproducible and comparable experimental data. The article profoundly points out that although the luminescence dissymmetry factor is widely used as a core performance metric, its measured values are deeply influenced by a combination of the material system (e.g., lanthanide complexes, organic molecules, perovskites), physical state (solution or thin film), and instrumental settings. This leads to systematic biases in extensive literature data, making direct comparison difficult (Figure 17a). To this end, the authors not only meticulously analyzed specific pitfalls in CPL measurements for various materials (such as spectral resolution for lanthanide complexes, reabsorption effects for organic molecules, and anisotropy artifacts in solid-state thin films) but also provided a universal practical guide ranging from sample preparation and parameter optimization to data processing. Specifically, the authors noted that while commercial photoelastic modulator systems have enhanced the feasibility of CPL measurements, they may still introduce non-chiral polarization interference in low-signal regions. Therefore, the paper recommends employing polarization analysis systems based on the Stokes-Mueller matrix for critical studies. As discussed earlier, through the Stokes parametersS = (S0, S1, S2, S3), the intrinsic CPL of the sample can be separated and quantified from apparent polarization signals. Regarding optical path design, different excitation-detection geometries (such as orthogonal or backscattering detection) should be combined with sample rotation and flipping operations to effectively identify and suppress measurement errors caused by orientation or optical anisotropy. In terms of supplementary material parameters, the article calls on researchers to move beyond the sole pursuit ofglumand systematically report comprehensive performance metrics, including molar extinction coefficient, photoluminescence quantum yield, excited-state lifetime, and CPL brightness, to objectively evaluate the practical potential of materials. Especially in solid-state or aggregated systems, it is essential to clearly specify the sample preparation method, morphology, and aggregation state. It is recommended to verify the origin and stability of chiroptical signals through concentration gradient experiments, variable-temperature CPL tests, and enantiomer/racemate controls. The significant importance of this work lies in (Figure 17b), as it shifts CPL research from a practice inclined towards showcasing "best results" to a new stage emphasizing rigorous processes, data transparency, and cross-validation, laying a methodological foundation for establishing reliable performance benchmarks across the entire field.
The establishment of this standardized framework points out clear directions and higher requirements for future research. First, at the methodological level, it requires researchers to deepen their thinking from "what to measure" to "how to measure." In the future development of novel CPL materials, systematic optical characterization must be treated as an indispensable step, actively adopting methods such as enantiomer versus racemate controls and sample anisotropy evaluation for self-validation, to ensure that the reportedglumvalues truly reflect the intrinsic chiroptical activity of the material. Second, at the material design level, the differences in CPL mechanisms across various systems revealed in this paper (such as f-f transitions of lanthanide ions, excited-state relaxation of organic molecules, and valley spin characteristics of perovskites) suggest that pursuing high performance cannot rely solely on empirical exploration but must be combined with in-depth theoretical simulations. This will clarify the causal chain from molecular structure and aggregation state to macroscopic polarized emission, achieving a leap from "screening" to "design." Finally, regarding practical applications, the framework advocates thatBCPLand other comprehensive indicators will become more important; it forces researchers to balanceglum, quantum efficiency, and absorption coefficient, promoting the transition of materials from the laboratory to real-world application scenarios such as circularly polarized OLEDs and quantum information encoding. In summary, embracing and developing this standardized paradigm will greatly facilitate the reliable construction of chiral luminescent material databases and the accurate analysis of structure-activity relationships, ultimately accelerating their practical deployment in cutting-edge optoelectronic technologies.
6 Conclusion and Outlook
The creation strategies for circularly polarized luminescence materials are undergoing a paradigm shift from reliance on single chiral sources to multi-level synergistic regulation. This article systematically reviews two mainstream construction pathways: intrinsic chiral emitters based on precise chemical synthesis and chiral photonic environments relying on assembly techniques. At the molecular and nanoscale, chiral organic compounds, complexes, and inorganic nanostructures directly impart chiral optical activity to materials through core chemical bonds and spatial configurations; their advantages lie in the definiteness and modifiability of molecular structures, serving as the cornerstone for achieving high photoluminescence quantum yields. At the mesoscopic and macroscopic scales, cholesteric liquid crystals, chiral polymers, and elastomers effectively amplify or even induce strong CPL signals by constructing long-range ordered helical superstructures, while integrating advanced functionalities such as stimulus responsiveness and flexible wearability, although their performance highly depends on assembly precision and stability. The core challenge for future material creation lies in the deep integration of these strategies to achieve full-chain precise control over "molecular chirality-supramolecular ordering-photonic bandgap," thereby simultaneously optimizing the asymmetry factor, luminescence efficiency, and material stability.
The widespread application of CPL materials fundamentally benefits from the unique attributes of circularly polarized signals as high-order, dynamic, and difficult-to-replicate information carriers. In the field of information security, CPL expands encryption dimensions from traditional intensity and color to polarization states; combined with patterning technologies and stimuli-responsive materials, it significantly raises the security threshold for anti-counterfeiting and encryption. At the forefront of display technology, CPL light sources, serving as natural carriers for generating circularly polarized light, can be directly applied to 3D displays and near-eye imaging systems, effectively simplifying optical architectures and reducing visual crosstalk, making them one of the key materials regarded as breaking through bottlenecks in next-generation display technologies. In chemical and biosensing, CPL probes convert enantiomer recognition into dual readouts of fluorescence intensity and polarization direction, providing analytical methods with higher selectivity and sensitivity than conventional fluorescence sensing. The flourishing development of these multidimensional applications, in turn, imposes higher requirements on signal robustness, process compatibility, and device stability of materials under complex real-world conditions, driving in-depth research in application-oriented material chemistry and device engineering.
Reviewing the development of the circularly polarized luminescence (CPL) materials field, its research focus has evolved from initial material exploration and performance optimization to a stage of systematic construction oriented toward solving key bottlenecks in practical applications. Looking to the future, progress in this field will increasingly depend on the synergistic advancement of three factors: depth of mechanism exploration, precision of regulation, and technical standardization. Prospective research directions are expected to focus on: (1) Computation-driven rational design, utilizing artificial intelligence and machine learning to transcend traditional "trial-and-error" models, achieving efficient prediction of new materials with ultra-high asymmetry factors and ideal optoelectronic properties. Although computational simulation and machine learning have demonstrated potential in screening molecules with high asymmetry factors, they still face enormous challenges in predicting complex aggregated structures, solid-state luminescence efficiency, and material performance under actual device environments.[44]. Future development relies on the construction of high-quality, standardized datasets; (2) developing cross-scale precision manufacturing technologies to achieve precise programming of the chirality, direction, and intensity of CPL signals. Crucially, as the need for communication within the field and industrialization becomes increasingly urgent, promoting the standardization of measurement specifications and data reporting has become the cornerstone for ensuring that research results are reproducible, comparable, and inheritable. Through deep interdisciplinary integration and full-chain innovation, CPL materials are bound to play an even more central role in future information, display, and biotechnology sectors, driving the field toward maturity and standardization.
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