Origin of defect related green emission in rod shaped ZnO synthesized by eco friendly approach

Abstract

Rod shaped Zinc oxide (ZnO) Nanoparticles were synthesized by Sol-gel method via environmental friendly approach using a cucum sativa fruit peel extract as biosolvent and reducing agent. These process practices edible material as solvent which is non-toxic and utilizes waste material to synthesize ZnO nano rods. We also investigated the effect of different concentration of biosolvent on crystallite size, morphology and optical studies on ZnO were done systematically. Higher concentration of biosolvent induced reduction in particle size which was confirmed by X-ray diffraction (XRD) and Scanning electron microscopy (SEM). Higher band gap was observed for Z-25CP due to Burstein–Moss effect. Room temperature Photo luminescence (RTPL) of Z-25CP exhibited two peaks, one peak corresponds to Near band edge emission (NBE) and another prominent peak at 516 nm corresponds to deep-level (DL) emission which might be due to singly ionized oxygen vacancy (Vo). The mechanism for the green luminescence which is deep level emission was explored based on defects sites. These singly ionized oxygen vacancy which may create ferromagnetism can be a promising candidate for applications in Dilute magnetic semiconductor (DMS).