Effects of the Molar Ratio on the Photo-Generated Charge Activities of ZnO-TiO2 Composites

Abstract

In this study, optical properties of ZnO-TiO2 nano composite materials grown on Si substrates by Sol-gel method were investigated. The optical properties of thin films obtained with different molar ratio of the two semiconductors were characterized using visible UV spectra. The energy band gap of the photodiodes was calculated as 3.32 eV, 3.19 eV and 3.16 eV for undoped TiO2, 1:5 ZnO doped TiO2 and 1:2 ZnO doped TiO2 composites, respectively. Electrical properties of the ZnO: TiO2 composites were assessed where capacitance – voltage and Current – voltage measurements were performed. It was determined that the band gap energy of TiO2 photodiodes decreased and the diodes showed light sensitive properties with the improved ZnO doping.