Thermoelectric materials are one kind of functional materials which can directly realize the interconversion of thermal energy and electrical energy and have a promising application prospect in the fields of thermoelectric refrigeration and power generation. Currently, the low conversion efficiency limits the applications of thermoelectric materials. How to improve and optimize the thermoelectric figure of merit becomes very important in the current research. Cu₂Se-based phonon liquid thermoelectric materials are one new type of high performance thermoelectric materials with extremely low thermal conductivity by their special crystal structure, the researches of which have greatly promoted the development of thermoelectric materials. Cu₂Se undergoes a structural phase transition at high temperature, where the Cu atoms become the freely migrating liquid-like Cu ions. This special liquid-like behavior of Cu ions leads to the lower lattice thermal conductivity of materials by strong phonon scattering. In this paper, the Cu₂Se-based phonon liquid thermoelectric materials are focused on. The basic properties, special crystal structure and applications of Cu₂Se are summarized. The research achievements, preparation methods as well as the performance optimization means of Cu₂Se-based thermoelectric materials are introduced elaborately. Finally, the future research aspects and new ideas for improving the performance of phonon liquid thermoelectric materials are also analyzed and prospected.
Contents
1 Introduction
2 Properties of Cu₂Se and Cu₂Se-based phonon liquid thermoelectric materials
2.1 Properties of Cu₂Se
2.2 The concept of Cu₂Se-based phonon liquid thermoelectric materials
3 Development of Cu₂Se-based phonon liquid thermoelectric materials
3.1 Preparation methods of Cu₂Se-based phonon liquid thermoelectric materials
3.2 Performance optimization means of Cu₂Se-based phonon liquid thermoelectric materials
4 Conclusion