Fabrication and electrical characterization of CdO thin films: Diode applications

CdO thin films were deposited on p-Si and glass substrates by sol-gel spin coating method. X-ray diffraction (XRD), ultraviolet-visible (UV/Vis) spectrophotometer and atomic force microscopy (AFM) were used to investiate some properties of material. From these data, cubic crystal structure, surface consisting of nanoparticles and the band gap of 2.29 eV were confirmed, resepectively. CdO/p-Si heterojunction shows rectifying and photodiode behavior, evaluating the current-voltage (I-V) characteristics in dark and under light. The photocurrent increases with increasing illuminating intensity. While CdO/p-Si heterojunction shows photodiode property, solar cell performance need to improve, showing the open circuit voltage (Voc) of 128 meV. CdO/p-Si heterojunction diodes exhibited a non-ideal behavior with the ideality factor greater than unity that could be ascribed to the interfacial layer, interface states and series resistance. Results shows that CdO/p-Si heterojunction can be used as a photodetector in the optoelectronic applications.