Structural transformations of TiO2 films with deposition temperature and electrical properties of nanostructure n-TiO2/p-Si heterojunction diode

Titanium oxide (TiO2) films have been deposited on p-Si substrates by sol-gel method using spin coating technique. Structural and morphological properties were studied as a function of deposition temperatures by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The deposition temperatures were chosen from 700 °C to 1100 °C. Crystallization of the anatase phase and its transformation to the rutile phase were observed at 700 °C and 800 °C, respectively. The fabrication of nanostructure n-TiO2/p-Si heterojunction diode was formed by using T7 film deposited at 700 °C. The electrical parameters such as barrier height (ϕb) and ideality factor (n) of nanostructure n-TiO2/p-Si heterojunction diode were investigated by using I-V measurements and observed to be 0.58 eV and 5.39, respectively. Also, the values of ϕb and series resistance (Rs) were determined by using Cheung's and Norde methods. From the I-V measurements taken at room temperature, the space charge limited (SCLC) mechanism was determined at the low voltage region. The obtained results showed that n-TiO2/p-Si heterojunction diode is a good candidate for the applications of semiconductor electronic devices.