Systematic study of Ni, Cu co-doped ZnO nanoparticles for UV photodetector application

ZnO nanoparticles co-doped simultaneously with Ni and Cu at concentrations varying between 0 and 10% were synthesized by wet chemical method. The resulting nanoparticles were less than similar to 60 nm. At 5% Ni + 5% Cu co-doping, enhanced visible luminescence between 380 nm - 460 nm is seen. Coupled with a low bandgap of 3.4 eV, they result in conducive optical properties for application of this material as UV Photodetector. Marginal changes in bond length (similar to 0.003 angstrom) and c/a ratio (similar to 0.002 angstrom), along with absence of impurity phases reflect its microstructural superiority. Morphological studies indicate marginal reduction of interplanar spacing due to doping, thus, forming uniform crystalline nanoparticles. The nominal composition of Zn, O, Ni and Cu without any impurity phases remains intact. An overall blue shift in absorption peak for all samples than bulk ZnO is observed, emerging due to size effects. However, at doping concentrations higher than 5%, Cu (111) and Ni (200) phases are seen due to clustering. Electrical studies under UV exposure are in agreement with the characterization studies on the sample, showing highest responsivity, current gain and high quantum efficiency values of 10.003 mA, 1.0421 and 3.146% respectively. These properties enable 5% Ni + 5% Cu co-doped ZnO nanoparticles to be explored for use as a material for optoelectronic devices like UV Photodetector.

Automated summary

ZnO nanoparticles co-doped with Ni and Cu at varying concentrations show enhanced visible luminescence and conducive optical properties for UV Photodetector applications. Microstructural superiority, marginal changes in bond length and absence of impurity phases support their potential use in optoelectronic devices. Electrical studies under UV exposure demonstrate highest responsivity, current gain, and quantum efficiency, making them promising materials for optoelectronic applications.