Controlling the Mott–Peierls transition in epitaxial VO2 (M1) film grown by PLD for near-IR photodetection

Vanadium dioxide (VO2) (M1) exhibits a unique metal–insulator transition (MIT) near room temperature, garnering considerable attention for its applications in bolometer, terahertz/infrared detectors, and microelectronic devices. Here, we explore the potential of epitaxially grown VO2 (M1) thin films for near-infrared (IR) detection by optimizing the growth conditions, followed by structural characterization and device fabrication. Alongside the VO2 (M1) phase, two other oxides from the vanadium oxide family, VO2 (A) and V2O5, were also grown on a c-cut sapphire substrate using a pulsed laser deposition (PLD) system. In-depth analysis using temperature-dependent XRD and Raman spectroscopy confirmed the crystalline structure and the quality of epitaxial thin film formation of VO2 (M1), while also unveiling structural phase transition (SPT) behavior and the critical temperature of transition. At elevated temperatures during electrical measurement, the VO2 (M1) epilayer exhibits a first-order phase transition from the metallic to the insulating state, accompanied by a significant change in resistance exceeding three orders of magnitude unveiling its potential in thermal switches, memory-based devices etc. In depth, electrical analysis on all the grown oxides shows that VO2 (M1) and V2O5 exhibit a higher temperature coefficient of resistance (TCR) (3%/K and 2%/K) and a lower 1/f noise (in the order pA/Hz at 0.1 Hz) as compared to VO2 (A), paving scope for further analysis of these two oxides toward important applications in the domain of thermal sensors. Additionally, VO2 (M1) exhibited good bolometric response (in the order of ms) to IR radiation, proving its candidature for the application in IR detectors as well.