Green synthesis of ZnO and Mg doped ZnO nanoparticles, and its optical properties

The Zinc oxide nanoparticles (ZnO NPs) and Magnesium doped ZnO nanoparticles (Mg doped ZnO NPs) are synthesized by Psidium guajava leaf extract. X-ray diffraction studies confirmed that, synthesized nanoparticles were retained the wurtzite hexagonal structure. In FESEM and HRTEM image analysis, ZnO and Mg doped ZnO NPs morphology were trigonal and spherical shape. Elemental compositions were identified by EDAX analysis. From FTIR result, the Zn–O stretching was observed at 453 and 448 cm−1 for both ZnO samples. In Raman spectra, the high intensive E2high mode observed for 438 cm−1 for ZnO NPs. But Mg doped ZnO NPs intensity of E2high mode decreased as compared to the pure ZnO NPs, it is due to the Mg2+ ion in to ZnO lattice site. The photoluminescence measurements revealed that the broad emission was composed of seven different bands due to zinc vacancies, oxygen vacancies and surface defects.