一维铝背栅单晶硅薄膜太阳能电池光吸收分析

Optical Absorption of One-Dimensional Aluminium Back Grating Crystalline Silicon Thin Film Solar Cell

分别以铝、银、硅为一维背栅设计了三种单晶硅结构的薄膜太阳能电池.利用时域有限差分法,在入射光为300nm^1100nm的波长段,计算了三种背栅材料的单晶硅薄膜太阳能电池单晶硅层的光吸收效率;利用计算所得到的磁场强度分布特点,分析了600nm以上波长段光吸收增强的机理.定义了归一化光吸收密度的概念,以定量衡量给定波段的光吸收效率.通过比较三种太阳能电池的归一化光吸收密度和短路电流密度,发现铝背栅比硅背栅和银背栅能更加有效地提高单晶硅薄膜太阳能电池的全波段光吸收效率.

A structure of crystalline silicon thin film solar cell consisting of one-dimensional back graitngs and alumininum metal reflection was designed.Silicon,silver and aluminium were used as the back gratings′materials respectively.The finite-difference time-domain simulations were conducted to compute crystalline silicon′s optical absorption between wavelength of 300 nm and 1100 nm.To analysis the mechanism of optical absorption enhancement,magnetic field intensity distrubutions above wavelength600 nm were plot.Normalized optical absorption density was defined to measure optical absorption of full band quantitatively.Together with short-circuit current,it was used to compare full band optical absorption of three kinds of crystalline silicon thin film solar cells.In contrast,aluminium back gratings enhance crystalline silicon′s optical absorption most efficiently.