有机无机复合膜发光器件的研究

Color Variable Light-emitting Deives from Organic/inorganic Composite Film

针对聚合物电致发光(EL)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ZnO:Zn与空穴型聚合物材料poly(2,5-bis(dodecyloxy)-phenylenevinylene)(PDDOPV)成功制备了结构为ITO/PDDOPV/ZnO:Zn/Al的有机/无机复合膜双层器件。复合膜器件的发光效率与亮度比单层器件提高了1个数量级以上,而复合膜的电流是单层器件的0.5倍。而且,聚合物/无机物复合膜器件的发光颜色随电压的增加而蓝移,其光致发光(PL)光谱也随激发波长的改变而改变,有可能形成了新的发光基团。

To overcome the lack of electron type polymer which can be used in polymer electroluminescent（EL） devices, using n-type semiconducting inorganic material ZnO：Zn as electron transport layer and p-type semiconducting polymer poly（2,5-bis （dodecyloxy）- phenylenevinylene） （PDDOPV） as hole transport layer,the device covered the organic/inorganic composite film with the structure ITO/PDDOPV/ZnO：Zn/Al is successfully fabricated, The highest ratio of the luminescent efficiency of heterojunction device to that of single layer device of PDDOPV is 38.6 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 the increase of luminescent brightness and efficiency. A very interesting phenomenon is that the EL spectra blue-shift with the increase of applied voltage and the different PL spectra are obtained at different excitation wavelength,we attribute this phenomenon to the conformation of new light-emitting unit.