Impact of substrate temperature on the microstructure, electrical and optical properties of sputtered nanoparticle V2O5 thin films

Abstract: Applying reactive direct current (DC) magnetron sputtering method, nanoparticle vanadium pentoxide thin films were deposited onto glass slides and KBr substrates at different substrate temperatures. The films were characterized by X-ray photoelectron spectroscopy and atomic force microscope. Infrared spectra were recorded with a Fourier transform infrared spectrophotometer. It was found that, excepting the compositions, the film growth and vanadium oxygen bonds were strongly affected by the substrate temperature. Electrical measurements indicated that the square resistances of films showed an exponential decrease from 46 MΩ/□ to 33 kΩ/□ with substrate temperature increasing from 433 K to 593 K, and that the square resistance–temperature curves of films exhibited typical semiconducting behavior. Optical investigations were carried out in the near infrared and ultraviolet–visible range. Transmittance varied from about 95 to 55% in near-infrared range when the substrate temperature was elevated. In ultraviolet–visible range, optical band gaps and refractive indexes of films were deduced according to the transmission and reflection spectra. [ABSTRACT FROM AUTHOR]