Optical properties of hydrothermally deposited Ni and Co doped nanostructured ZnO thin films as scintillating coatings for beta-particles detection

Abstract

The optical properties of ZnO films doped with the Ni and Co transition metals that were hydrothermally deposited on a silicon substrate are discussed. The SEM, EDX, XRD and Raman spectroscopy studies showed that the films deposited have a compact crystalline structure and can be considered as nanostructured polycrystalline ZnO films doped with Ni and Co and designated as ZnO:Ni and ZnO:Co, respectively. Under optical and electronic excitation, the films demonstrated both near-band-edge ultraviolet and visible range luminescence due to crystal lattice defects. The highest intensity of the ultraviolet luminescence with a fast decay was achieved for the ZnO:Ni and ZnO:Co samples deposited in the 0.05 M solutions of Ni or Co nitrate salts. Wide luminescence spectra make the films obtained promising as luminophore or scintillating coatings for the beta-particles detection including structures integrated with silicon circuits, for example, solid state silicon-based radiation counters.