Si surface passivation by SiOx : H films deposited by a low-frequency ICP for solar cell applications

• Main Authors: Wei, D. Y., Zhou, H. P., Xu, S., Xiao, S. Q., Xu, L. X., Huang, S. Y., Guo, Y. N., Khan, S., Xu, M.
• Other Authors: Institute of Advanced Studies
• Format: Article
• Language: English
• Published: 2013
• Online Access: https://hdl.handle.net/10356/98502; http://hdl.handle.net/10220/12369
• Institution: Nanyang Technological University

Hydrogenated silicon suboxide (SiOx : H) thin films are fabricated by a low-frequency inductively coupled plasma of hydrogen-diluted SiH4 + CO2 at a low temperature (100 °C). Introduction of a small amount of oxygen into the film results in a predominantly amorphous structure, wider optical bandgap, increased H content, lower conductivity and higher activation energy. The minority carrier lifetime in the SiOx : H-passivated p-type Si substrate is up to 428 µs with a reduced incubation layer at the interface. The associated surface recombination velocity is as low as 70 cm s−1. The passivation behaviour dominantly originates from the H-related chemical passivation. The passivation effect is also demonstrated by the excellent photovoltaic performance of the heterojunction solar cell with the SiOx : H-based passivation and emitter layers.