基于一维光子晶体陷光的超薄晶硅太阳电池光学结构优化

Optimal Design of Ultrathin c-Si Solar Cell with Light Trapping Structure of One Dimensional Photonic Crystal

先选择增透膜、Ag底面反射镜和三角带型一维光子晶体结构作为超薄晶硅电池(有源层厚度为12μm)的陷光结构,然后利用有限差分频域法对这一陷光结构进行了优化,最后通过吸收光谱和光电流密度谱对优化的陷光结构性能进行了评估。计算表明:在300 nmλ800 nm的波长范围内,优化陷光结构实现了Yablonovith陷光极限;在800 nmλ1100 nm的波长范围内,该优化陷光结构的性能略低于Yablonovith陷光极限,但明显高于矩形条带式一维光子晶体陷光结构的陷光性能。

The bilayer antireflecting coating, Ag back reflector and front surface texture of one dimensional photonic crystal were first chosen as the light trapping structure of ultrathin silicon solar cell with its active layer thickness equal to 12 μm,then the light trapping structure were optimized by finit difference frequency domain method,and the performance of the optimal light trappingt structure was evaluated by absorptance spectra and photocurrent density spectra. The results show that the optimal light trapping structure can achieve the performance of Yablonovith light trapping structure in the wavelength range from 300 nm to 800 nm and it can also achieve a performace lower than that of Yablonovith light trapping structure in the wavelength range from 800 nm to 1100 nm,but its light trapping performace is obviously higher than that of the light trapping structure of one dimensional photonic crystal with rectangular profile.