We report on the fabrication of p-Si/n-CdO and p-Si/n-CdIn2O4 junction diodes using chemically prepared pure CdO and In 5–20 wt.%-doped CdO nanoparticles. The cadmium oxide (CdO) and indium-doped cadmium oxide (ICO) nanoparticles were characterized using x-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy, energy dispersive analysis, high-resolution transmission electron microscopy (HRTEM), UV-Vis analysis, photoluminescence (PL) and electrical conductivity measurements. The strongest orientation along the (111) plane for CdO indicates a fcc crystal system. The average particle size of ICO nanoparticles vary from 26 nm to 41 nm. The FTIR bands for ICO samples at 508–511 cm−1 was strongly remodeled while increasing the doping concentration of In at 15 wt.%. HRTEM revealed a clear spherical morphology ~16.28 nm of average particle size for the ICO with 20 wt.% In. Moreover, a maximum electrical conductivity of 15.084 × 10−10 S cm−1 with higher transmittance range of about 76.11% was achieved. The photosensitivity of the p-Si/n-CdIn2O4 diode varied from 103 to 104 %. Also, high quantum efficiency ~225.92% and specific detectivity 5.1952×1011 Jones were found for p-Si/n-CdIn2O4 photodiode. These outcomes suggest that the developed p-Si/n-CdIn2O4 diode is suitable one in the fabrication of UV photodetector and solar cell devices for electronic communication.