Study on the optoelectronic properties of Zn and Mg doped CuGaO2 nanoplates

In this study, significant optoelectronic performance boost was observed after Mg and Zn doping of hexagonal CuGaO2 (CGO) nanoplates (NPs) by the hydrothermal method. Details effects of dopant are studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), absorption spectra, and photoluminescence (PL)spectrum. There is a sharp peak at 700 nm in the PL spectrum of pure CGO NPs ascribed to the intrinsic defect caused by Cu vacancy (VCu) and the peak increases dramatically in intensity as elements doping. To deeply understand the enhancement mechanism in PL intensity of Zn-doped CGO (ZCGO) NPs and Mg-doped CGO (MCGO) NPs, the band diagram and radiation transition of divalent ions doped CGO NPs are investigated in detail. These results reveal that the divalent element doping (ZCGO especially) could increase the carrier concentration of CGO material effectively and form stable and high-intensity PL emission. In addition, photodetection performance of pure CGO NPs and doping CGO NPs has been demonstrated, which could be enhanced by constructing non-planar heterojunction of nanoplate and ZnO nanowire arrays. And Zn doping has a significantly better effect than Mg doping in absorption, photoluminescence and ultraviolet (UV) detection. The findings can play an important role in the regard of optoelectronic performance enhancement of CGO NPs, which common used in optoelectronic devices such as red light emitters and ultraviolet (UV) detectors.