Unravelling the silicon-silicon dioxide interface under different operating conditions

Silicon dioxide (SiO2) has played a critical role in the development of high-efficiency silicon (Si)-based photovoltaic devices. Recently, it has experienced a renaissance as an interlayer in many of the new contact passivating structures. Studies have extensively investigated the recombination process at the Si-SiO2 interface, however, only little is known about the impact of temperature on the surface recombination. In this study, we investigate the recombination at the Si-SiO2 interface by varying the temperature, excess carrier density, and dielectric fixed charge. An improved lifetime is observed with increasing temperature. A forming gas anneal is used to improve the passivation quality, however, at higher temperatures, the hydrogenated interface passivation degrades due to increased surface state density. The degradation is stronger for corona-charged SiO2, due to the instability of the corona charge within the dielectric. Using the extended Shockley-Read Hall recombination model, the Si-SiO2 interface defects' parameters are extracted. Most importantly, we determine the value and the temperaturedependence of the capture cross-sections at this interface.

Automated summary

Silicon dioxide has been crucial in the development of high-efficiency silicon-based photovoltaic devices, with studies showing improved lifetime as temperature increases. However, passivation of the hydrogenated interface degrades at higher temperatures. A forming gas anneal can improve passivation quality.