Long-term stability of low-temperature deposited Cat-CVD SiNx thin film against damp-heat stress

Abstract

In this paper, we systematically investigated the damp heat (DH) stability of silicon nitride (SiNx) films formed by catalytic CVD (Cat-CVD) at low substrate temperatures (T sub) of 100 °C-137 °C, aiming at application as a gas barrier and antireflection layer of perovskite/silicon tandem solar cells. We have found that the optical properties of the SiNx films, such as refractive index and reflection of the films, were changed only slightly for <2% after DH testing for >500 days. The Fourier transform IR spectroscopy studies demonstrated that the SiNx films were hardly oxidized under the DH test for the sample formed at high T sub. A slight oxidization occurs only in the SiNx film formed at a low T sub of 100 °C after DH testing for 274 days. These results indicate the high stability of the Cat-CVD SiNx films and their feasibility for application in the surface coating of solar cells.