We describe a simple but efficient technique for fabricating heterojunction diodes by simply depositing undoped and Cr-doped CuO thin films on n-Si substrates, and we investigate the electrical properties of diodes for different mixing ratios of chromium oxide and copper oxide. The results show that a change in CrO and CuO concentration significantly affects the electrical properties of Ag/Cu1 − xCrxO/n-Si diodes. The all diodes exhibit rectification behavior, as shown by their dark I-V characteristics. The crucial junction parameters such as series resistance (Rs), rectification ratio (RR), ideality factor (n) and barrier height (ΦB) were calculated by using I-V data. the characteristics of capacitance-voltage (C-V), conductance-voltage (G-V) and series resistance-voltage (Rs-V) were measured in the frequency range of 10 kHz to 1 MHz. The obtained results demonstrate that the electrical properties of the Ag/Cu1 − xCrxO/n-Si diodes are controlled by the different mixing concentration ratios of chromium oxide and copper oxide content.