Theoretical Analysis of Optical Losses in CdS/CdTe Solar Cells

Based on the known refractive index and extinction coefficient, calculations of optical losses in glass/transparent conducting oxide/CdS/CdTe solar cells have been carried out taking into account reflections at the interfaces and absorption in the transparent conducting oxide (indium tin oxide or $SnO_2$:F) and CdS layers. It has been shown that the losses caused by reflections at the interfaces result in lowering the short-circuit current by ≈ 9% whereas absorption in the transparent conducting oxide and CdS layers with the typical thicknesses lead to losses of 15-16% for glass/$SnO_2$/CdS/CdTe, and 22-24% for glass/indium tin oxide/CdS/CdTe solar cells.