Morphological and optical property study of Li doped ZnO produced by microwave-assisted solvothermal synthesis

ZnO materials have been at the centre of many studies for decades. Doping of ZnO by lithium atoms is a prospective approach for compensation of n-type conductivity in the unintentionally doped ZnO aimed at obtaining p-type semiconductor. In this study, we have synthesized ZnO rod-like powders doped with lithium ions (0–0.65 atom%) by the new microwave-assisted solvothermal method in order to obtain greater photoluminescence intensity of ZnO emissions in the UV region. The obtained powders contain nanoparticles from 20 nm up to 250 nm depending on Li content. X-ray diffractometry and Raman spectroscopy were employed to characterise the structure of ZnO powders, scanning electron microscopy was used to determine the morphology, and most importantly the photoluminescence technique was used to investigate the optical properties of the obtained materials. As a result, the photoluminescence intensity has been increased up to an order of magnitude with the Li content in the ZnO crystals. The increase of the excitation laser power has led to an increased carrier lifetime and photoluminescence response intensity that is observed for all the samples.