In this study, IGZO thin films were produced on SLG and p-Si wafer at low temperature, under oxygen gas pressure of 5×10 -2 and 7×10 -2 mbar, using PLD technique and these thin films were annealed at 300 o C temperature. IGZO thin films were grown in amorphous structure. As the oxygen gas pressure was increased, the particle size in the thin films were increased. IGZO/p-Si heterojunction diode was produced based on IGZO thin film that was deposited under oxygen pressure in 7×10 -2 mbar and not annealed, and − curves of this diode in darkness and under the illumination condition were obtained and then its barrier height and idelaity factor were calculated. In an illumination condition, , and Ф values of IGZO/Si heterojunction diode were calculated by the traditional − , Norde and Cheung Cheung methods. Results obtained in this work have been interpreted as well as concluded to be close to each other.