Temperature Dependence of Silicon-Dielectric Interface Recombination

Abstract

Investigations into the temperature dependence of the surface recombination at the interface between silicon and various dielectrics in modern solar cells are of significant interest as they (a) provide fundamental information regarding the interfaces, and (b) allow to improve predictions regarding the performance of solar cells under actual operating conditions. In this study, we use a novel technique based on external bias voltages to control the carrier population at the silicon-oxide/silicon, silicon-nitride/silicon, and aluminum-oxide/silicon interfaces from heavy accumulation to heavy inversion in the temperature range 25–90 °C. We find that the effective lifetime slightly increases at elevated temperatures when the imbalance of the carrier populations is amplified. In the studied temperature range, it seems that the electron and hole capture cross-sections at all the interfaces are temperature-dependent. The technique offers a simple and versatile manner to separate the chemical passivation from the charge-assisted population control at the silicon/dielectric interface, as a function of temperature. It can be very useful for the optimization of the dielectric layers and the investigation of the fundamental properties of the passivation at this interface.