Impact of Pd²⁺ and Sn⁴⁺ co-doping ZnO nanoflakes toward high-performing Schottky diode based on the generation of intermediate bands within the energy gap

Pd:Sn/ZnO nanohybrid was prepared by chemical co-precipitation route and identified using XRD, EDX, SEM, and TEM techniques. The microstructure analysis emphasized the polycrystalline nature in which Pd and Sn ions were substituted inside ZnO framework to form the nanocomposite. The surface morphology was appeared in 2D nanoflakes with large specific surface area. The optical parameters including E_g, n, and k were deduced from T% and R% spectra through wavelength range 300–1400 nm. The thin film showed strong optical absorption inside the UV region with a value of E_g = 3.10 eV. The Ag/Pd:Sn/ZnO/p-Si/Al Schottky diode was fabricated by thermal evaporation technique, and its electronic and photodetector properties were investigated from I–V and C–V measurements. The fabricated device exhibited non-ideal behavior with high rectification ratio RR = 935 and a relatively small R_s lies between 2365 and 2755 Ω. Under illumination impacts, the photodiode exhibited high photosensitivity and responsivity attributed to the large photo-induced charge carriers.