Electrical and optical transport characterizations of electron beam evaporated V doped In₂O₃ thin films

Vanadium (5 at. %) doped Indium Oxide (V: In₂O₃) thin films with different thicknesses (50 nm, 100 nm and 150 nm) were prepared onto glass substrate by electron beam evaporation technique in a vacuum of about 4 x 10^-3 Pa. X-ray diffraction (XRD) pattern revealed that the prepared films of thickness 50 nm are amorphous in nature. Temperature dependence of electrical resistivity was studied in the 300 < T < 475 K temperature range. The films exhibit a metallic behavior in the 300 < T < 380 K range with a positive temperature coefficient of the resistivity (TCR), whereas at T > 380 K, the conduction behavior turns into a semiconductor with a negative TCR. Optical studies revealed that the films of thickness 50 nm possess high transmittance of about 86 % in the near-infrared spectral region. The direct optical band gap lies between 3.26 and 3.00 eV depending on the film thickness. (author)