Influence of Annealing on Photoluminescence of ZnO:Mn Thin Flims Grown by Sol-Gel Technique

ZnO:Mn thin flims were fabricated by Sol-gel technique. the effect of annealing time on the photoluminescence (PL) properties of the prepared flims has been investigated. The room temperature PL of ZnO:Mn films is shown to consist of an UV emission band due to radiative recombination of free excitons and a weak green band signated as the radiative transition from Zn vacancies(VZn) to Oxygen antisites. It is shown that whereas increasing annealing time make both of emission bands increase, an enhacement for the relative intensity of green emission compared to that of UV emission is obtend. Meanwhile, An increse of saturation magnetizations was also observed. All results provided clear evidences that although the annealing have the effect of ameliorate the microstructure of ZnO:Mn flim, the accompanied increased VZn defects make the magnetic moments become more alignd. Keywords-sol-gel; ZnMnO; PL; ferromagnetism; VZn