Investigation the Performance of Cr-Doped ZnO Nanocrystalline Thin Film in Photodiode Applications

Undoped and Cr-doped zinc oxide (ZnO) thin films were deposited on the glass and p-Si substrates by the chemical spray pyrolysis technique. The films were characterized by x-ray diffractometry (XRD) and UV-visible spectrometry, and electrical characterization was achieved by using the films as an interfacial layer between the Au and p-Si. The XRD results confirmed the undoped and Cr-doped ZnO thin film crystalline structures. UV-visible spectra provided the transmittance plots and band gap energy values. I-V measurements were performed on the fabricated Au/ZnO/p-Si and Au/ZnO:Cr/p-Si devices to determine the effect of the ZnO interfacial layer on their performance. Various junction parameters, such as the ideality factor, barrier height, and series resistance, were calculated from the I-V measurements by various techniques, and have been discussed in detail. A 100-mW/cm(2) power intensity light was exposed on the Au/ZnO:Cr/p-Si device to see the photodiode behavior as well as to determine light sensitivity parameters such as photosensitivity and detectivity. The results highlight that the Au/ZnO:Cr/p-Si device can be thought of for optoelectronic applications.