Effects of annealing temperature on current-voltage characteristics of TiO2 thin film by sol-gel process on silicon substrate for biosensor application

TiO₂ thin film was deposited on a silicon dioxide substrate using a sol-gel method and the film was annealed at 300, 500 and 700°C. Aluminum interdigitated electrodes were fabricated on the deposited TiO₂ thin film via simple lithography method. The influence of thermal annealing towards the morphological and electrical properties were studied. X-ray diffraction (XRD) shows that crystalline rutile structure growth at very low temperature whereas field emission electron microscopy (FESEM) exhibits nanoparticles with an average 21 mm in size. The current flows between the fabricated interdigitated electrodes were extremely small at -5 to 5 V applied which were decreased as the annealing temperature increases with average barrier height was 0.8 eV.