Elevated Transition Temperature of VO₂ Thin Films via Cr Doping: A Combined Electrical Transport and Electronic Structure Study

V_1−xCr_xO₂ (0 ≤ x ≤ 0.3) (VCO) thin films were deposited onto r-sapphire substrates using a pulsed laser deposition method. The electronic structures of these compounds were investigated by x-ray photoemission spectroscopy (XPS), and the electrical transport measurements by four-probe electrical resistivity along with the Hall effect measurements. The XPS study shows that the valency of the Cr ions in the VCO films is 3 + and the V ions are in mixed states of 4 + and 5 + . From the resistivity-temperature measurements, the metal–insulator transition (MIT) temperature (T_C) of Vanadium dioxide (VO₂) increases significantly upon Cr doping, while the hysteresis width and resistivity follow a gradual decrease. These findings will pave the way for the usage of VO₂ films in solar and electrical device applications where larger critical temperatures than pristine VO₂ are required.