Optimization Of Light Trapping Structure Of Silicon Thin Film Solar Cells

Solar energy is the most dominant renewable energy source among all new energy sources.Silicon-based solar cells have a long history and mature technology,and are the most important photovoltaic devices.How to improve the photoelectric conversion efficiency of solar cells is the key to solving their application costs.To increase the light absorption rate of the cells,the maximum light energy is the technical problem that needs to be overcome.Therefore,various light trapping structures have become hot spots for scientific researchers.Based on the research progress of solar cells at home and abroad,this dissertation focuses on the key issues of improving the light absorption of the cells and uses the surface plasmon effect to study the optical properties of various light-trapping structures on the surface of silicon-based materials.Two kinds of structures that enhance light absorption are designed on the surface of silicon-based materials,namely metal nano-gratings and metal silver nano-spheres.The influence of three light trapping structures on the light absorption characteristics of amorphous silicon is systematically studied,and the optimized structure parameters are obtained.1.Silver nano-gratings are designed on the surface of amorphous silicon thin-film solar cells.TM waves,TE waves and TEM waves are perpendicularly incident on the surface of the cell.Effects of different structural parameters on light absorption are studied and optimized.Determine the best geometrical parameters for different application conditions.After optimization,the number of absorbed photons of the cells is 92% of the reference cells.2.Using the surface plasmon polariton effect,the Ag nano-grating on the back surface was studied,and two structures of triangular columnar and rectangular cuboid silver nanostructures were designed.The results show that silver nano-gratings have higher absorptivity than aluminum nano-gratings.In both structures,the rectangular cuboid nanograting has the highest light absorption rate,which is 102% higher than that of the reference cell.And the sensitivity of the incident light angle has also been improved.3.Based on the local surface plasmon resonance,the light absorption effect of the silver nanosphere cells arranged in different distribution modes was compared.The results show that the radius,period,and distribution position all have an effect on the light absorption of the silicon thin film.Among the three distribution methods,the light absorption effect was evenly distributed on the front and back surfaces,which was 50% higher than the reference cells.The light trapping structure can effectively enhance the light absorption of the thin film cells,and provides theoretical support for the design and development of thin film solar cells.