Optoelectronic characterization of ZnO obtained by green synthesis of Zn-salt precursor in parsley extract

Highlights: • ZnO synthesized in parsley extract at 80 °C shows hexagonal morphology. • Parsley extract plays an important role during the synthesis of crystalline ZnO. • ZnO synthesized in parsley extract incorporates Mg in the ZnO matrix. • ZnO obtained by green synthesis shows a band gap lower than commercial ZnO. ZnO was obtained by reducing Zn salt in parsley extract at 80 °C. Structural and morphological characteristics of ZnO obtained by green synthesis were compared with ZnO acquired commercially and ZnO synthesized by simple water reduction. XRD and EDS suggested the presence of Mg traces in the ZnO synthesized in parsley extract. In this case, the incorporation of Mg in the crystalline structure of Zn-O was investigated by analyzing the changes in the c-parameter of the wurtzite structure. The analysis by SEM showed a well-defined hexagonal morphology of particles. Raman Spectroscopy was used to measure the optical and longitudinal vibrations of ZnO:Mg. The calculated band gap for ZnO:Mg was lower than commercial ZnO. The decrease in the band gap energy was attributed to the presence of atomic Mg in the ZnO lattice. The photoluminescence activity of ZnO:Mg was mainly observed at the UV, blue and green regions.