Selenization of V2O5/WO3 bilayers for tuned optoelectronic response of WSe2 films

Abstract

Scalable and controlled doping of two-dimensional transition metal dichalcogenides is essential for tuning their electronic and optoelectronic properties. In this work, we demonstrate a robust approach for the substitution of vanadium in tungsten diselenide (WSe2) via the selenization of pre-deposited V2O5/WO3 thin films. By adjusting the thickness of the vanadium oxide layer, the V concentration in W1−xVxSe2 is systematically varied. Electrical measurements on field-effect transistors reveal a substantial enhancement in hole conduction, with drain current increasing by nearly three orders of magnitude compared to undoped WSe2. Temperature-dependent electrical resistivity indicates a clear insulator-to-metal transition with increasing V content, likely due to band structure modifications. Concurrently, the photoconductive gain decreases, suggesting enhanced recombination and charge screening effects. These results establish vanadium doping via selenization of V2O5/WO3 films as a scalable strategy for modulating the transport and photoresponse of WSe2, offering promising implications for wafer-scale optoelectronic device integration.