High-Performance Amorphous Silicon Thin Film Solar Cells Prepared at 100 °C: Toward Flexible Building-Integrated Photovoltaics

Abstract

For low-cost and lightweight polymer/plastic substrates in flexible building-integrated photovoltaic (BIPV) modules, low-temperature processing is essential. Amorphous silicon (a-Si:H) requires processing at a temperature of 200–250 °C by plasma-enhanced chemical vapor deposition to obtain satisfactory optoelectronic properties, which limits such substrates in terms of thermal budget. This study is focused on the fabrication of p–i–n-type a-Si:H solar cells at relatively low temperatures (100 °C). Intrinsic a-Si:H films with large optical gaps (1.83 eV) were prepared at 100 °C using a high hydrogen dilution ratio. In addition, p-type amorphous silicon oxide and n-type microcrystalline silicon oxide films with large optical gaps and suitable conductivities were prepared at 100 °C using a gas mixture containing the dopant B2H6 or PH3 and CO2. Finally, an a-Si:H p–i–n cell was fabricated at 100 °C; it exhibited an excellent power conversion efficiency of 9.0%, which was higher than those reported for a-Si:H thin film photovoltaics prepared at 100 °C. We believe that this study will open promising routes for the development of high-performance and flexible BIPVs.