Effects of non-stoichiometric ratio on optical characteristics of Mg-doped ZnO nanorods

Abstract In this study, light scattering properties of Mg-doped ZnO Nanorods were easily adjusted by hydrothermal process through Non-stoichiometric ratio (Zn1MgxO1, x = 0.2–1). X-ray diffraction, scanning electron microscopy (SEM), UV-Vis spectrophotometry and photoluminescence revealed that Mg ions substituted the Zn sites without changing the hexagonal wurtzite structure. This was accompanied by gradually decrease in tensile stress due to increased Zn/Mg ratio from 1:0.2 to 1:0.8. The average diameter of NRs rose from ∼75 to 90 nm and turned into a plane with water ripple as Zn/Mg ratio enhanced to 1:1. The light scattering ability and optical constants of MgZnO NRs exhibited significant wavelength dependency, which exponentially declined as wavelength increased. The higher relative intensities of the visible peak recorded for MgZnO NRs testified of the elevated oxygen vacancies density when Zn/Mg ratio enhanced from 1:0.6 to 1:1. Overall, the proposed method looked promising as facile and novel way for adjusting light-trapping abilities of MgZnO NRs thin films suitable for polymer solar cells and other ZnO-based optoelectronic and photonic devices.