ZnO荧光粉中的紫外发射和绿色发射之间的关系(英文)

The Relationships between UV Emission and Green Emission in ZnO Phosphor

通过在低氧分压和真空中热处理ZnO粉末,获得了ZnO荧光粉．ZnO荧光粉有两个发射谱带,分别位于380 nm(紫外)和510 nm(绿色)．紫外谱带对应于ZnO中的激子发射,是一个单中心发光过程;绿色谱带是一个复合发光过程,与ZnO中的本征缺陷相关,如氧空位、锌空位等．实验表明,高密度的激发条件有利于紫外发射,而低氧分压下的热处理有利于提高绿色发射谱带的强度．研究结果还表明,与紫外发射相联系的激子可向与本征缺陷相联系的绿色发光中心传递能量,这种传递可能是通过激子扩散实现的．

ZnO phosphor was synthesized by annealing ZnO powder at low O5 partial pressure and in vacuum. ZnO has two emissions, which are located at about 380 nm （UV emission） and 510 nm （green emission）. The UV emission can be attributed to the exciton emission, which is a single-center process, whereas the green emission is related to native defects, such as Vo^＊ and Vza＇, which is a two-center （donor-acceptor） recombination process. The high-density excitation favors the UV emission, whereas the green emission likely appears in the samples annealed at low O2 partial pressure. It was shown that the energy transfer may occur from the UV emission center to the green emission center, and the exciton diffusion mechanism for the transfer was proposed.