PNNL

Abstract

Thin films of as-deposited As2S3 glass developed a white haze under ambient conditions. To study this surface degradation, we evaluated the effects of visible light, oxygen, humidity, and temperature. X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) were used to characterize the surface of these films. Results showed that As2S3 films simultaneously exposed to light and humidity formed arsenolite (As2O3) crystals on the film surface, correlating with the observed haze. A dry and dark environment is concluded to provide the best protection for storing As2S3 thin films. Additionally, a water vapor barrier layer was shown to inhibit degradation under typically corrosive conditions.