ZnS:Mn、Cu粉末直流电致发光器件直流和交流电致发光一致性的研究

本文研究了粉末直流电致发光(DCEL)器件在直流(DC)和交流(AC)电压下光电特性的关联和区别及其物理机制.实验发现,在DC和AC条件下DCEL器件的阻抗特性之间没有任何有规律的关联,而AC条件下的激发电流IA和亮度BA以及DC条件下的亮度BD和发光效率ηD四个参量之间则表现出某种程度的一致性,但AC条件下的发光效率ηA与上述四个参量之间却表现出某种相反和相对立的关系.DCEL器件的光电特性具有强烈非线性和对电压方向的非对称性.正半周(或DC条件下)DCEL器件是在高电场和低电流激发下的发光.对发光起主要作用的是电场强度.在负半周时则是低电场和大电流激发下的发光.对发光起主要作用的是激发电流而不是电场强度.在AC条件下依材料、工艺、形成条件和工作电压的不同,DCEL器件可能更多地显示出正半周,负半周或两半周综合的光电特性.上述观点可以解释本文的实验结果.

STUDY OF THE CONSISTENCE IN DCEL AND ACEL CHARACTERISTICS OF POWDER ZnS:Mn,Cu DCEL DEVICES

In this paper,the relations and differences between DCEL and ACEL characteristics of powder ZnS:Mn,Cu DCEL devices,and their mechanism are investigated.Experiments show that the impedance characteristics both under DC and AC voltage operations are not consistent and related.But the exciting current IA and the brightness BA under AC voltage,and the brightness BD and the efficiency ηD under DC voltage tend to consistency to certain extent.The efficiency ηA under AC voltage is contrary to above four parameters.DCEL devices are strongly non-linear and non-symmetrical in photoelectric characteristics.In positive half-cycle of AC voltage(or under DC voltage),DCEL devices are excited by high electric field and low current.Under this circumstance,the luminance is dominared by electric field.On the contrarily,in negative half-cycle of AC voltage DCEL devices are operated by low electric field and large current.At this case,the luminance is dominated by current,no;by field.Under AC voltage,the luminance of DCEL devices may show characteristics of positive or negative half-cycle,or complex characteristics of both positive and negative half-cycle,depending on the phosphors,the art of devices,the forming process and operation voltage.The above point of view can explain all of the experimental results mentioned in.this paper.