Study on the Ohmic Contact, Electrical and Optical Properties of Nanostructured Titanium Dioxide Thin Films

摘要

Nanostructured Titanium Dioxide (TiO_2) thin film with various sol-gel concentrations has been successfully prepared using sol-gel spin coating method. Nanostructured TiO_2 thin films prepared at different sol-gel concentration from 0.1M to 0.4M. The IV measurement was measured using direct currents between two contacts were measured using Advantest source meter (R6243). To perform the IV measurement, two kinds of metal contact has been used; Platinum (Pt) and Gold (Au). It showed that both of metal contact shows that 0.2M of concentration gives the lowest sheet resistance. The sheet resistance and resistivity of the thin film decreased from 0.1M to 0.2M and significantly increased at 0.3M and 0.4M. Optical transmission spectra were recorded in the wavelength range 200-1000 nm using UV–VIS–NIR Spectrophotometer (VARIAN 5000). The effect of sol concentration on band gap (Eg) values of the TiO_2 thin films has been studied. The lowest band gap is 3.35eV which contribute to 0.2M of concentration and it is also understand that prepared nanostructured TiO_2 thin film is indirect band gap.