Characteristics of metal contact to GaS films and photodetector applications

Abstract

Group-III monochalcogenides, particularly gallium sulfide (GaS), have garnered attention for visible–UV range optoelectronic applications owing to their wide bandgap, which can reach approximately 3 eV. The interplay between group-III monochalcogenides and metal electrodes needs to be understood to optimize the device performance. In this study, we explored the Schottky barrier height between GaS deposited through atomic layer deposition and commonly employed Ti/Au electrodes through low-temperature current–voltage measurements. The GaS photodetector exhibited p-type transport characteristics with a mobility of 7.71 × 10^–1 cm² V⁻¹ s⁻¹ and a photoresponsivity of 547 A W⁻¹.