Because of their exceptional properties, Mn-doped ZnO nanocrystals are attracting much attention as semiconductor nanomaterial. Undoped and four levels (1%, 2%, 3% and 4%) of manganese doped Zinc Oxide were synthesized using co-precipitation procedure. Mn doped ZnO was characterized using XRD, photoluminescence spectrometer (PL), and optical band gap energy (Eg) measured by UV-visible. The results show that, no signature of impurity peaks appeared in the XRD pattern of the samples that elucidate Mn attached secondary phases. The 4% manganese doped Zinc Oxide has the lowest particle size.
The optical energy band gap was found to be 2.85 eV for undoped ZnO samples, 2.5 eV for 1% Mn-doped samples and 2.1 eV for 4% manganese doped Zinc Oxide. The results show decrease in the optical band gap through rising Mn concentration this might attributed to many discussed reasons. While there's no change within the magnitude of the optical band gap for the Zinc Oxide and Mn doped ZnO samples after irradiation with gamma ray at a dosage of 30 kGy.
The intensity of the PL peak of Mn doped ZnO shows a decrease after irradiation with gamma ray dosage of 30 kGy. The decrease in the PL intensity refers to the reduction of oxygen vacancies due to the indigent interface between ZnO/Mn. In the photoluminescence spectra, ultraviolet emission was recorded for the doped and undoped samples at a wavelength of 368 and 471 nm respectively and other smaller peak emissions. So, Mn-doped ZnO nanoparticles can be used as dilute magnetic semiconductors.