聚合膜/无机膜异质结电致发光机理研究

Electroluminescence from Heterojunction Consist of Polymer Film and Inorganic Film

针对聚合物电致发光材料缺乏可用的电子型聚合物半导体材料的现状 ,采用无机电子型半导体材料 Zn O∶Zn与空穴型聚合物材料 PDDOPV[poly(2 ,5 - bis(dodecyloxy) - phenylenevinylene) ]成功制备了结构为 ITO/PDDOPV/Zn O∶ Zn/Al的异质结双层器件。异质结器件的发光效率与单层器件 P的发光效率的比值在电压为 8V时达到最高值38.6倍 ,此时异质结器件的亮度是器件 P的 19.4倍 ,异质结的电流是单层器件的 0 .5倍。结果表明 ,Zn O∶ Zn薄膜的插入 ,确实能够起到输运电子和阻挡空穴从而降低器件电流水平 ,提高器件发光效率的作用。而且 ,聚合物膜 /无机膜异质结器件的发光颜色是随着电压的增加而蓝移的。研究认为有可能是形成了新的发光基团。

Aim at overcoming the lack of electron type polymer can be used in polymer electroluminescent devices, using n type semiconducting inorganic material ZnO:Zn as electron transport layer and p type semiconducting polymer PDDOPV [poly (2,5 bis (dodecyloxy) phenylenevinylene)] as hole transport layer, device based on heterojunction with structure ITO/PDDOPV/ZnO∶Zn/Al is successfully fabricated. The highest ratio luminescent efficiency of heterojunction device to that of single layer device of PDDOPV is 38.6 times at 8 V, and brightness and current of heterojunction device are 19.4 times and 0.5 time of that of single layer device respectively. The results demonstrate that the insertion of ZnO∶Zn layer can transport electrons and block holes that lead to the decrease of current and increase of luminescent brightness and efficiency. A very interesting phenomenon is the emitting color blue shifts with the increase of applied voltage. New light emitting unit may be engendered.