In this work, the impact of gamma-ray irradiation (gamma) on graphene/Al2O3/p-type Si structure has been investigated. For this, temperature-sensitive current-voltage (I-V) analyses of the structure exposed to gamma radiation have been carried out. I-V measurements have been made between -3 V and 3 V to analyze electrical properties of the graphene/Al2O3/p-type Si before and after Co-60 gamma-irradiation. I-V measurements of the structure have been made at the range of 300 K-405 K. Thermionic emission (TE) theory and Cheung's methods have been used to examine the electrical features of the structure. The discrimination of all experimental results has been done by using Principal Component Analysis (PCA). In PCA analysis, the first two principal components (PC1 = 75.6% and PC2 = 20.9%) accounted for 96.5% of the variance, which is a very good result.