Impact of front TCO layer in substrate-type thin-film microcrystalline silicon solar cells

In the recent 3 years, power conversion efficiencies in thin-film microcrystalline silicon solar cells were remarkably improved from 10.1% to 11.8%. Front transparent conductive oxide films play an important role in this efficiency improvement. In this study, the impact of the front transparent conductive oxide films were investigated by comparing microcrystalline silicon solar cells with In₂O₃:Sn films grown by sputtering and ZnO:B films grown by metal-organic chemical vapor deposition. The origins of the improvement in open circuit voltages and fill factor in solar cells were investigated and discussed.