Elevated Transition Temperature of VO 2 Thin Films via Cr Doping: A Combined Electrical Transport and Electronic Structure Study

V 1− x Cr x O 2 (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 (VO 2 ) 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 VO 2 films in solar and electrical device applications where larger critical temperatures than pristine VO 2 are required. Graphic Abstract