Band gap tunability in DC sputtered Ni-doped ZnO thin films for wide usage in optoelectronic gadgets

ZnO thin films have brought significant applicability in optoelectronic and energy storage devices based on their environmental friendliness. Pristine ZnO, 6.25% and 12.5% Ni-doped ZnO thin films were deposited on Si substrate via direct current and radio frequency magnetrons, respectively. The X-ray diffraction patterns exhibited phase purity of synthesized thin films. The micrographs showed reduction in average grain size for pure ZnO, 6.25% and 12.5% Ni-doped ZnO as 95 nm, 70 nm and 60 nm, respectively. The elemental purity was confirmed by energy dispersive X-ray. The ellipsometric analysis showed that Ni inclusion brought band gap variation from 3.06-3.08 eV for pure ZnO to 12.5% Ni-doped ZnO thin films. The real part of dielectric constant enhanced from 3.60 to 3.75 for 12.5% Ni-doped ZnO, simultaneously depicting reduction in dielectric loss from 0.45 to 0.40. Conclusively, proposing Ni-doped ZnO thin films with low dielectric loss as a potential candidate in optoelectronic industry.