Exceptionally tunable electronic, optical and transport properties of two dimensional GaS doped with group II and group IVa elements

Abstract

In this present study, we systematically investigated the structural, electronic, optical and transport properties of pristine and group II, group IVa doped GaS monolayers using density functional theory (DFT). The strong formation energy suggests realization of group II & group IVa doped GaS. A semiconductor to metallic transition occurs in GaS monolayer with doping.Moreover, doped GaS monolayers have shown tunable optical properties. Doped GaS monolayers show optical activity in both ultraviolet (UV) as well as visible region. EEL spectra of GaS shift towards high energy region (red shift) with group II elements doping while no significant shift is observed for group IVa elements doping in both the polarizations. We found quantum conductance of 4G 0 for doped GaS monolayer except for Be-doped GaS. The metallic character of doped GaS is clearly captured in tunneling current characteristics showing ohmiclike characteristics for doped GaS monolayer. This is due to finite density of states associated with S atoms of doped GaS. The doping extends the functionalities of pristine GaS with tunable properties suggesting doped GaS as a potential candidate for use in photo-diodes, photocatalysts, photo-detectors and bio-sensing.