INVESTIGATION OF OXYGEN-RELATED DEFECTS IN ZnO: GROWING TIME AND Mn CONCENTRATION EFFECTS

Abstract

The optical and photoluminescence properties of ZnO nanocrystals synthesized via hydrothermal method are determined in this study. The effect of growing time (1 h, 6 h, 12 h, 24 h and 36 h) and Mn concentration (5x10-4 mol, 10x10-4, 25x10-4 mol, 75x10-4 mol, 100x10-4 mol, 250x10-4 mol) on these properties are investigated and presented in detail. The ultraviolet-visible (UV-Vis) and photoluminescence (PL) spectroscopy techniques are used for optical and photoluminescence properties characterization. Room temperature PL spectra of the ZnO nanopowders show a near band-edge emission (peak at 385 nm) and a red light emission (peak at 650 nm) for both ZnO synthesized for different growing time and different Mn concentration. The ZnO prepared with 1 h and 12 h includes the lowest oxygen related defects. The ZnO doped with 5x10-4 mol shows the highest oxygen related defects whereas that of 100x10-4 mol shows the lowest defects.