太阳电池用金属背反镜的吸收损耗

Absorption Loss of Metal Back Reflector for Solar Cells

利用频域有限差分法计算获得的金属背反镜吸收损耗谱及其光电流密度谱,分析了c-Si、a-Si和GaAs三种材料电池的银背反镜的吸收损耗情况。分析过程中,电池结构采用两种形式,即平板型和织构型,且两种形式的电池结构具有相同的有源层厚度、减反膜结构、缓冲层结构、银背反镜厚度。分析表明:直接带隙a-Si和GaAs材料的银背反镜损耗小于间接带隙c-Si材料;平板型电池银背反镜的TE模损耗随入射角增加而减小,TM模损耗随入射角增加而增加;织构型电池银背反镜吸收谱的吸收峰较平板型电池多,相应的银背反镜的损耗也较平板型电池大;TM模激励的等离子体振荡吸收效应在织构型电池中表现明显。

Using the finite difference method to calculate the absorption loss spectra and the optical current density spectra of the metal back mirror, the absorption loss of the metal back mirror with three kinds of materials, c-Si, a-Si and GaAs, were analyzed. In the process of analysis, battery structure was used in two forms., the flat plate type and textured type, and two forms of cell structure had the same thickness of the active layer, antireflection film structure, buffer layer structure, silver backed mirror thickness. Analysis shows： The direct band gap of a-Si and GaAs materials with the silver back reflector mirror loss is less than the indirect band gap c-Si material ~ The loss of the TE mode of the flat panel type battery cell bank is decreased with the increase of the incident angle, and the loss of TM mode increased with the increase of the incident angle;The absorption peak of the texture type cell is more than that of the flat plate, and the loss of the corresponding silver back reflector mirror is larger than that of the flat panel; TM mode excitation of the plasma oscillation absorption effect is obvious in the texture cell.