Excitons and Photoluminescence in ZnO and Zn0.99Mn 0.01O Nanocrystals

Abstract

The photoluminescence and photoluminescence excitation spectra for Zn 1-x Mn x O nanocrystals are presented. After annealing of powders in air, the intensity of the bands attributable to manganese decreases noticeably. This suggests that the oxygen vacancies affect the Zhang-Rice-like states appearing due to strong d-p-hybridization, which is confirmed by an increase in the band gap of Zn1-x Mn x O for low x. The origin of the 2.9-eV peak and the shape of its excitation spectrum are discussed qualitatively. For Zn1-x Mn x O nanocrystals, the shape of the excitation spectrum is as unusual as the intense absorption in the range (2.2-3.0) eV. © 2010 Pleiades Publishing, Ltd.