ZnO Doped with Alkali Metals Serving for Optoelectronic Applications

Abstract

A nitrate-glycine route combustion synthesis of ZnO and ZnO doped with Li, Na, K and is précised here along with the structural and optical properties. The XRD patterns of the samples clearly indicate the wurtzite hexagonal structure of the samples. Due to the difference in the ionic radii of the dopants, a minor variation is observed in the lattice constants. The undoped ZnO has the smallest grain size; ZnO: Li has the second smallest grain size followed by ZnO: Na and then ZnO: K. The UV-Vis-NIR spectra of the samples are utilized to calculate the photon band gap. The band gap shows a considerable red shift for all dopants. The fluorescence spectra of the samples have a weak UV emission and a dominant emission in visible region. The visible emission shows a blue shift whereas the UV emission shows a red shift down the alkali group. The observed tuning capability of the band gap and the photo luminescent properties in the materials could greatly find applications in optoelectronic industry.