微波吸收法研究ZnS:Mn粉末发光材料的光电子瞬态过程

本文采用微波吸收介电谱技术,测量了ZnS:Mn材料受到紫外超短脉冲激光激发后,其光生电子的瞬态衰减过程,得到了ZnS:Mn材料光电子衰减时间分辨谱.分析表明,光电子衰减由快慢两个衰减过程组成,快过程持续时间约为10ns,慢过程近似为指数衰减过程.Mn的掺杂浓度对导带光电子的寿命有明显的影响,慢过程光电子寿命随着Mn掺杂浓度的增加而呈下降趋势,掺杂浓度由0.10;质量分数增加到1.00;质量分数时,慢过程的光电子寿命由779ns下降到363ns,下降了近一倍.这是由于随着Mn掺杂浓度的提高,Mn2+发光中心的密度增加,导带光电子与发光中心的碰撞几率增大,寿命降低.

Investigation of Decay Process of Photoelectrons of ZnS:Mn Luminescent Materials by Microwave Absorption Method

The decay process of photoelectrons of ZnS:Mn luminescence materials after excitation with short pulse laser was investigated by using microwave absorption dielectric spectrum detection technique. The photoelectron time-resolved spectra of ZnS:Mn materials were obtained. The results indicate the presence of two decay components of photoelectrons, i.e. the fast component with duration of 10ns and the slow component with lifetime of 490ns. It is found that the concentration of Mn has an evident influence on the lifetime of photoelectrons in conductive band. The lifetime of photoelectrons in the slow decay component decreases obviously as increasing the concentration of Mn. The lifetime of photoelectrons decreases from 779ns to 363ns when increasing the doping concentration from 0.10wt% to 1.00wt%. This is due to the factor that the colliding probability of photoelectrons with luminescent centers increases as the concentration of Mn 2+ increasing.