Abstract
In this work, pure NiO and NiO:Cu based photodetectors with different concentrations of Cu dopants (0, 0.5,1.0, and 1.5 wt%) were coated on glass substrates by using a simple, low cost nebulizer spray pyrolysis technique. Their structural, morphological, optical (UV–Vis absorption and photoluminescence), and ultraviolet (UV) sensing features were characterized with state-of-the-art analytical techniques. The structural studies confirm that the prepared films have crystalline nature and possess a cubic structure. From the absorption measurement, the optical bandgap (Eg) of the deposited films decreases with the increase in Cu dopants. Photoluminescence study illustrates that 1.0% of Cu doping significantly improves the physical property of the NiO:Cu films and also its UV sensing study suggests that the 1.0% of NiO:Cu film could be better suited for high-speed optoelectronic devices due to their high Responsivity (0.202 AW-1), External quantum efficiency (47%), and Detectivity (5.9 × 109 jones) values. A possible mechanism of the photodetector performance under air and UV illumination is also discussed in this work.
•First time investigation on Cu insists of NiO films based UV photodetector by simple nebulizer spray method.•Reported the increase of photocurrent with respect to bias voltage for enhancing photoelectric properties.•Decrease of the optical bandgap for Cu doped films due to the observed redshift in absorption and higher crystallite size.•Maximum responsivity, external quantum efficiency, and specific detectivity were observed for the 1% Cu doped NiO detector.•A possible mechanism for enhancing photocurrent under UV illumination was also discussed with a schematic diagram.