Light Trapping Efficiency Enhancement Of The Photovoltaic Devices Based On SiO₂ And TiO₂ Nanostructures

Photovoltaic power generation is one of the key directions of future energy development,and the most widely used solar cells are silicon-based solar cells.The key to improving the photoelectric conversion efficiency of silicon-based solar cells lies in how to achieve high-efficiency absorption of light and enhancement of the photovoltaic effect.Nanostructures show great advantages in the field of light trapping and efficiency enhancement of silicon based solar cells due to their special size effect that can enhance light trapping.In this paper,SiO₂and TiO₂,which are dielectric materials with low light loss,low cost and high stability,are used as basic materials of light trapping structure to prepare crystalline silicon solar cells with SiO₂,SiO₂@TiO₂ and TiO₂ hollow nanospheres array structure.The optical and photovoltaic properties of these cells are studied by combining experiment and simulation.First,the modified St(?)ber method is used to prepare SiO₂ nanospheres with uniform particle size;then SiO₂ nanospheres are used as templates to prepare SiO₂@TiO₂core-shell structured nanospheres by the sol-gel method;and further,TiO₂ hollow Nanosphere is obtained by lye etching.The three nanospheres of SiO₂,SiO₂@TiO₂ and TiO₂ hollow are hydrophobically modified,and then the Langmuir-Blodgett(LB)method is used to self-assemble the three nanospheres,so that they are regularly arranged on the surface of the crystalline silicon solar cell.The experimental results show that the coverage rate of the SiO₂ nanosphere array on the surface of the crystalline silicon solar cell is 95%,the coverage rate of the SiO₂@TiO₂ nanosphere array is 87%,and the coverage rate of the TiO₂ hollow nanosphere array is about 80%.Secondly,the influence of nano-array structures of different particle sizes on the optical performance and photovoltaic performance of crystalline silicon solar cells was explored.The experimental results show that the 550 nm SiO₂ nanosphere array has relatively better anti-reflective light trapping effect than other SiO₂ nanospheres,with an average reflectivity of 27.22%.The photovoltaic conversion efficiency is 8.97%higher than that of a battery without a nanoarray;For the SiO₂@TiO₂ nanosphere array,the nanospheres with a particle size of550 nm have a relatively low average reflectance(27.69%),and the photovoltaic conversion efficiency is increased by 9.24%;for the TiO₂ hollow nanosphere array,the450 nm nanospheres have a relatively low average reflectance(30.06%),and the photovoltaic conversion efficiency has increased by 6.68%.Finally,COMSOL simulation software was used to construct a crystalline silicon solar cell with SiO₂,SiO₂@TiO₂,TiO₂ hollow nanosphere arrays(particle size 300,450,550 nm),and the optical and photovoltaic performance of the above nanoarray on the crystalline silicon cell was calculated and analyzed.And conducted a comparative study of three kinds of nano-structure photovoltaic light trapping synergies.The results show that under the same particle size,the performance of solar cells based on TiO₂ hollow nanosphere array structure is better than that of SiO₂@TiO₂ and SiO₂ nanoarray structures.