Reduction of Optical Loss in Hydrogenated Amorphous Silicon/Crystalline Silicon Heterojunction Solar Cells by High-Mobility Hydrogen-Doped In₂O₃Transparent Conductive Oxide

Hydrogen-doped In 2 O 3 (IO:H) films with high electron mobility and improved near-infrared transparency have been applied as a transparent conducting oxide (TCO) electrode in hydrogenated amorphous silicon (a-Si:H)/crystalline silicon heterojunction solar cells. The incorporation of IO:H, instead of conventional Sn-doped In 2 O 3 , improved the short-circuit current density ( J sc ) and the resulting conversion efficiency. Detailed optical analysis of the solar cells revealed that the improvement in J sc is due to the reduction of reflection loss at the TCO/a-Si:H interface and less optical absorption in the TCO layer.