Achieving stable LaVO₃ without a reducing atmosphere: Zn/Sb doping toward non-halide perovskite photoconductive devices

Abstract

Pure and doped LaVOx, (x = 3, 4) thin films were successfully deposited using reactive magnetron sputtering, a physical process of depositing thin films, known as physical vapor deposition (PVD). The addition of Zn and Sb led to structural and morphological transitions. Sb doping led to the monoclinic LaVO₄ phase, while Zn doping produced the orthorhombic LaVO₃ phase without the usually required reducing atmosphere. Morphological studies showed that Sb-doped films had smooth, dense surfaces, while Zn-doped films exhibited columnar growth with increased roughness. Optical characterization revealed a diminution in the band gap with Sb doping, 3.52 eV in comparison to the 3.57 eV band gap observed for undoped LaVOx. The lowest band gap for Zn doping was found to be 3.19 eV. Electrical measurements revealed enhanced photoconductivity under white light, with Zn-doped films demonstrating a sharper photoresponse despite lower conductivity. This study provides the first demonstration of the possible transition of LaVO 4 to LaVO₃ thin films in ambient air through Zn and Sb B-site doping using magnetron sputtering, without the need for a reducing atmosphere. The findings open a new pathway toward sustainable, non-halide oxide perovskites for photovoltaic and photoconductive device applications. • Stable LaVO₃ thin films were achieved without a reducing annealing atmosphere. • Zn doping stabilizes orthorhombic LaVO₃ (Pnma) phase with magnetron co-sputtering deposition. • Band gap tuned from 3.57 eV for undoped to 3.19 eV for Zn-doped samples. • AFM and SEM reveal dopant-dependent morphology: columnar growth for Zn doping vs dense for Sb doping. • Simple devices showed photoconductive behavior in all the deposited films.