Enhancement of UV detection properties of ZnO thin films via Ni doping

Abstract

In this work pure and Ni-doped ZnO thin films have been deposited onto glass substrates using the spray pyrolysis technique. All films were deposited at constant deposition parameters but the Ni content was changed from 0 to 7 weight (wt) %. XRD results revealed the formation of a hexagonal ZnO phase whilst no other phases were detected. The crystallite size was determined using Scherrer's equation and found to be 45.9 nm for the pure film. Scanning electron microscope images show the formation of irregular grains with a broad size distribution. The existence of Ni in the deposited films was confirmed using energy dispersive spectroscopy (EDX), where the Ni content in the film increases as the weight % increases in the starting solution. The optical band gap was determined and found to be 3.3 eV for the pure ZnO films, which was reduced with Ni doping. The performance of the deposited films for UV radiation has been examined for the 365 nm wavelength and at different applied potentials and constant power. The rise and decay times for doped films were observed to exhibit faster rise/recovery as compared to pure films. The minimum response time was found to be 0.09 s for Ni-7wt% film and the minimum decay time is 0.07 s for Ni-1wt%.

Recent Advances in Solution-Processed Zinc Oxide Thin Films for Ultraviolet Photodetectors

“…The rise and recovery periods of the doped films were shorter than those of the pure films. The film with 7 wt % nickel had a minimum rise time of 0.09 s, whereas the film with 1 wt % nickel had a minimum decay time of 0.07 s. 86 Vanadium doping boosted the carrier density and created defect states, resulting in a considerable decrease in the electron−hole recombination rate and a high photocurrent when exposed to UV light. Compared to pristine ZnO-based PDs, the V/ZnObased PDs displayed a 156% increase in the photocurrent, as well as short reaction and recovery times.…”

Strong Magneto-Optical Kerr Effects in Ni-Doped ZnO Nanolaminate Structures Obtained by Atomic Layer Deposition

“…The chemically modified Zn(Ni)O composite nanostructures show an altered bandgap electronic structure with a significant effect on the physical properties. The most recent studies are focused on the following: (i) the main optical properties (absorbance, photoluminescence) and constants, photoconductivity and low optical losses, linear and non-linear (third order) optical susceptibilities with opto-electronic prospects in quantum technologies [10], photodetection [11] and solar cells with high detector responsivity; (ii) the development of enhanced catalyst function [12,13] and surface (gas species) adsorption in numerous green chemistry applications, especially for photo-chemical [14] and gas sensing applications [15]; and (iii) notable thermoelectric [16] and acoustoelectronic [15] (with larger insertion loss and phase shift) characteristics.…”