ZnO空穴缓冲层对OLED性能的影响  

Influence of Hole Buffer Layer ZnO on Properties of Organic Light-Emitting Devices

作　　者：贾许望[1] 关云霞[1] 牛连斌[1] 黄琳琳[1] 刘德江[1] 傅小强[1] 

机构地区：[1]重庆师范大学物理与电子工程学院,重庆400047

出　　处：《重庆师范大学学报（自然科学版）》2012年第2期72-76,共5页Journal of Chongqing Normal University:Natural Science

基　　金：国家自然科学基金(No.60806047);重庆市自然科学基金(No.2009BB2237;No.CSTC2011jjA90019);重庆市教委科学技术研究项目(No.KJ100613;No.KJ080816);中国博士后科学基金(No.20100481376);重庆高校创新团队建设计划(No.201013)资助项目

摘　　要：本文利用无机材料ZnO作为空穴缓冲层,制备了结构为ITO/ZnO/NPB/Alq3/Al的有机电致发光器件。用计算机控制的KEITHLEY2400-PR655系统测量器件的电压-电流-亮度特性。研究结果表明,当ZnO薄膜的厚度为2 nm时,器件的电流效率可达1.65 cd/A,最大亮度为3 449 cd/m2;而没有加入缓冲层的同类器件,最大亮度仅为869.7 cd/m2,最大电流效率为0.46 cd/A。由此可以看出,加入ZnO空穴缓冲层后,最大亮度提高3.97倍,最大电流效率提高3.59倍。分析认为适当厚度的ZnO薄膜降低了发光层空穴的浓度,提高了电子和空穴的复合率,从而降低了电流密度,提高了器件的电流效率,改善了器件性能。Organic light emitting diodes （OLEDs） ate very promising candidates for flat-panel device applications due to low power consumption, improved contrast, wide viewing angle, self-emission and brightness in comparison to liquid crystal or plasma displays. The efficiency of OLEDs is highly dependent on the carrier injection behavior. To improve efficiency of the device, we used inorganic material ZnO as hole buffer layer. The device was built on ITO （sheet resistance 20 Ω/□） glass which was thoroughly cleaned. After the oxygen plasma treatment, the substrates were loaded into a vacuum chamber with a base pressure of 4.0x 10 4 Pa. NPB, ZnO, Alq3 and electrode were thermally deposited without breaking tbe vacuum respectively. The structure was as follows： ITO/ZnO/NPB/ Alq3/A1. In conclusion, it was found that 2 nm the ZnO layer can greatly improve the performance of the organic light emitting diode. The improved efficiency of the device could be due to the ultra-thin ZnO layer acting as the decreased holes injection into the emissive layer, which would make the number of electrons and holes injected into the emitter layer balance.

关 键 词：有机电致发光器件 修饰层 ZNO 

分 类 号：TN383.1[电子电信—物理电子学] TN873.3