The sol-gel spin coating technique was employed for the deposition of thin films comprising CoOx, Cu-doped CoOx, and CuOx onto n-Si substrates. Subsequently, an exhaustive examination of the electrical properties of the resultant heterojunction structures was conducted. The outcomes unequivocally indicate that the incorporation of Cu through doping exerts a pronounced influence on the electrical attributes of the CoOx/n-Si diode. Notably, all diodes exhibit rectifying behavior, a discernible feature in their dark current-voltage (I-V) characteristics. The I-V data was further utilized to ascertain pivotal junction parameters, encompassing series resistance (Rs), rectification ratio (RR), ideality factor (n), and barrier height (ΦB). The values of the ideality factor for CoOx/n-Si, Cu doped CoOx/n-Si and CuOx/n-Si are obtained to be 3.19, 1.99 and 2.19 eV, respectively. Furthermore, the capacitance-voltage (C-V) characteristics of diodes were performed within the frequency range of 10 kHz to 1 MHz. These findings underscore that judicious manipulation of the copper doping concentration can serve as an effective means to modulate the electrical properties of CoOx/n-Si diodes.