Phase transition and corresponding influence on the yellow-orange Mn~(2+) emission of ZnS∶Mn~(2+) quantum dots

摘要

The Zn_(0.09)Mn_(0.01)S quantum dots have been synthesized with one-step hydrothermal method by adding oleic acid. By adjusting reaction temperature and time, the zincblende-to-wurtzite transition has been realized at relatively lower temperature of 190℃ and longer reaction time of 24 h. The effects of phase transition on both Mn~(2+) emission and defect emission have been investigated in detail. The yellow-orange emission from ~4T_1-~6A_1 transition of Mn~(2+) ions and blue-green emission originated from defects can be tuned by reaction temperature and time. Along with the phase transition happens in Zn_(0.99)Mn_(0.01)S QDs, both the concentration of different species of defects and the corresponding radiative transition channel spontaneously rearranged. The results testified that more defects exist in the Zn_(0.99)Mn_(0.01)S QDs with wurtzite structures.