The Study Of The Antireflection Structures For Photovoltaic Cells

Photovoltaic cell is an important photoelectric device that can convert optical energy into electricity and make use of it.The research of photovoltaic cells is mainly about how to improve the energy conversion efficiency to make sure efficient energy conversion.And the antireflection structures contribute to lower reflectance in a wide range of wavelength,to improve the incident light energy ratio effectively for the cells and to increase the energy conversion efficiency.This thesis focuses on the antireflection structures,where varied antireflection structures based on multilayers structures and nanopillar array structures were probed respectively.And the corresponding optimization schemes were proposed.The effect made by different schemes to cells'performance was analyzed through simulation and calculation.The work in this thesis can be divided into two parts as follow:1.Based on the multilayers antireflection structures,the preparation process of SiO₂materials through ICP-PECVD was studied and the preparation technologies of gradient refractive index SiO₂ films at low temperatures were developed.Based on the materials above,proposed a film structure considering both antireflection and encapsulation.Based on the simulating calculation about reflectance of the perovskite solar cells with different antireflection structures at the visible wavelength,found that the reflectance of cells with multilayers in gradient refractive index lowered 1.5% when compared with single layer one.Based on the simulating of cells'performance,found that the J_sc increased 1.98% and the energy conversion efficiency increased 1.89%in the cells with gradient refractive index multilayers when compared with the single one.2.Based on the nanopillar array antireflection structures,the antireflection property in different nanopillar arrays was studied.The wavelength where the minimum reflectance appeared in nanopillar array could be adjusted continuously from 400nm to 1000nm through the nanopillar height changing.Based on the properties above,the antireflection mechanism in mixed heights or radiuses nanopillar array and their different reflectance to different polarized light were studied.Based on the spectral superposition property to realize the antireflection in a wide range of wavelength and a lower-than 7% reflectance from 400nm to 800nm was realized in simulation when nanopillar array structure combined different heights nanopillars,60nm and 140nm.Through simulation,a lower-than 5% and broadband reflectance could be realized in different mixing nanopillar structures.Based on AFORS-HET,the influence made by the reflectance to the cells'performance was studied.And found that the mixing nanopillar structures could reduce the optical loss of Si-PEDOT:PSS solar cell in the visible band,improving the energy conversion efficiency.