The up and down conversion technology can convert the infrared and ultraviolet light into the visible light in the range of 300~800 nm, which can solve the energy loss caused by spectral mismatch, and the absorption spectrum of the cell can be expanded to improve the light utilization and conversion efficiency. The rare earth ion is often used as the center ion of the up and down conversion materials because of the special structure of the energy level and the high luminous efficiency. In recent years, the center ion of up conversion is mainly Er³⁺, Tm³⁺and the sensitization center is Yb³⁺ with longer excited state lifetime. Tb³⁺, Eu³⁺ and Sm³⁺ have charge transfer absorption band in the ultraviolet region, which can be easily excited by ultraviolet light and the emission spectrum mainly located in the visible region, so they are often used as the center ion of down conversion.The host is usually fluoride and the materials with high crystallinity, small particle size and uniform distribution were prepared by hydrothermal method. At present, the research on up and down conversion applied to DSC is getting more and more important. In this paper, we mainly discuss the application of up and down conversion in DSC, and prospect the future development direction.

Contents
1 Introduction
2 Up and down conversion technology
2.1 Luminescence mechanism of up and down conversion
2.2 Host of up and down conversion luminescent materials
2.3 Preparation method of luminescent materials
3 Application of up and down conversion in dye sensitized solar cells
3.1 Energy loss in solar cells
3.2 Application modeling of up and down conversion in solar cell
3.3 Application of up and down conversion luminescent materials in DSC
4 Conclusion and outlook