Effect of substrate temperature on the Ga-S films properties prepared by PECVD

Gallium sulfide (GaS) has a great potential for applications in optoelectronics and energy storage. In view of the sufficiently large Eg, thin films of gallium sulfide can be used as a buffer layer in a solar cell. GaS also provides efficient passivation of the GaAs surface. In this work, Ga-S thin films were obtained for the first time by plasma-chemical vapor deposition. High-purity elemental Ga and S were used as precursors. The plasma was excited by an RF generator (40.68 MHz) at a reduced pressure of 0.1 Torr. The composition, structural and optical properties of Ga-S films were studied depending on the substrate temperature. All films were highly transparent (75%) in the range of 400–1100 nm.