Analysis on micro-/poly-Crystalline SiGe Alloy Solar Cells

Abstract

Performance of micro-/poly-crystalline SiGe alloy solar cell of TCO/(n)a-Si:H/(i)a-Si/(p) c(pc)-SiGe/(p+)μc-Si/Al structure was analyzed via the AFORS-HET software. Cell structures can be designed to reach up to the optimal performance. Employment of back surface electric field layer of (p+)μc-Si could improve cell properties. The maximum photoelectric conversion efficiency η=21.48% occurs in a cell with average Ge percent content x0.1 and 250 m-thick Si1-xGex alloy light absorption layer, which is higher than the experimental result of the same absorption layer thickness crystalline Si HIT cell [Progress in Photovoltaics: Research and Applications, 8 (2000) 503.]. Temperature dependence of the cell performance parameters (open circuit voltage Voc, circuit current density Jsc, fill factor FF and efficiency η) indicates that Si0.9Ge0.1 cell shows weaker temperature sensitivity than that of pure Si cell. Numerical calculation illustrates that Voc decreases while Jsc, FF and η heighten with raising mean grain sizes and crystalline volume fractions, these variations with the later are more remarkable. Present optimized technique will be benefit to designing and fabricating the high performance solar cell.