退火和淬火对电致发光材料老化的影响

EFFECT OF ANNEALING AND QUENCHING ON ELECTROLUMINESCENT PHOSPHOR DETERIORATION

退火和淬火对交流粉末电致发光老化的改善是最有效的方法,原因尚未清楚。本文通过发射光谱、热释光和离子探针实验首次提出:在退火和淬火速冷过程中铜的分布发生了变化,由于铜的析出,聚集在晶体表面缺陷上,形成了高场所必需的硫化锌—硫化铜结,增加了晶体中场分布的不均匀性和势垒高度,稳定了硫化铜相,改善了场的分布和初电子注入条件,因而,改善了电致发光老化。

Annealing and quenching are the most efficient ways for electroluminescent materials to improve their maitenance. The reason why annealed and quenched phosphor has a long lifetime is not yet clear.By making the investigations on the emission spectrum, thermoluminescence and ion probe, it is found for the first time that the distribution of copper in a phosphor particle is changed by annealing and quenching. The copper is concentrated in a small region near the surface during quenching, And these regions correspond to copper sulfide segregation. Therefore, the reason why the annealed and quenched phosphor has a long lifetime may be considered to be that the copper sulfide segregation is stabilized by annealing and quenching, and the ZnS-Cu2S junction is formed. The distribution of electric field in a particle must be stringly deformed and concentrated near the surface. The field strength and potential barrier are increased and the condition of initial electron injection is improved, Thus the degradation of ACEL phosphor is alleviated,