倒置有机发光二极管中电子注入的研究及发展  

Progress and outlook on electron injection in inverted organic light-emitting diodes

作　　者：姜慧慧 肖静[1] 殷照洋 张连 杨红芳 高旭[2] 王穗东[2] Huihui Jiang;Jing Xiao;Zhaoyang Yin;Lian Zhang;Hongfang Yang;Xu Gao;Suidong Wang(School of Physics and Electronic Engineering,Taishan University,Taian 271000,China;Jiangsu Key Laboratory for Carbon-Based Functional Materials&.Devices,Institute of Functional Nano&Soft Materials(FUNSOM),Soochow University,Suzhou 215123,China)

机构地区：[1]泰山学院物理与电子工程学院,泰安271000 [2]苏州大学功能纳米与软物质研究院,江苏省碳基功能材料与器件重点实验室,苏州215123

出　　处：《科学通报》2021年第17期2105-2116,共12页Chinese Science Bulletin

基　　金：国家自然科学基金(61204051,61574098);山东省重点研发计划(2019GGX101016)资助。

摘　　要：在文化和科技迅速发展的时代,信息显示广泛应用于社会生活的各个领域.在众多新型显示技术中,有机发光二极管(organic light-emitting diodes,OLEDs)凭借高对比、广视角、高显色等优势成为新一代显示技术.多样的有机材料、简单的器件结构和制备技术给予它更多的发展可能.其中,倒置结构的OLEDs(inverted organic lightemitting diodes,iOLEDs)因与基于n型薄膜晶体管(thin film transistors,TFTs)的驱动电路具有更好的兼容性而备受关注.然而,iOLEDs器件中氧化铟锡(indium tin oxide,ITO)阴极与有机发光层的最低未占据分子轨道(lowest unoccupied molecular orbital,LUMO)之间存在较大能级差,较低的电子注入效率严重限制了器件性能.针对这一问题,本文综述了提升iOLEDs电子注入效率的研究进展,主要围绕Richardson-Schottky(RS)热注入和Fowler-Nordheim(FN)量子隧穿两种电子注入模型展开讨论.With the rapid development of science and technology,the traditional cathode ray tube(CRT)that was invented at the end of the 20 th century has revealed significant deficiencies such as high power consumption and large volume.In the secondgeneration flat panel display technology,i.e.,liquid crystal display(LCD)technology,deficiencies related to high cost and relatively mediocre response speed still exist.Users’dissatisfaction with LCDs subsequently led to the invention of organic light-emitting diode(OLED)displays.They were introduced to the public with wide-angle vision,high color contrast,fast response speed,low power consumption,and low cost.Most commercial active matrix OLEDs use low-temperature polysilicon(LTPS)thin-film transistor(TFT)backplanes.Although LTPS TFT can be used as a p-type transistor owing to its high carrier mobility,high availability,and high stability,it has problems of complex processing and uniformity being difficult to guarantee,which affect the display performance of OLEDs screens.Therefore,to pursue high resolution and stable display,research on inverted OLEDs(i OLEDs)is vital.The bottom cathodes of i OLEDs are connected to the drains of n-type TFTs for realizing better integrated circuits.In addition,indium tin oxide(ITO)has a high surface work function(approximately 4.8 e V),and for most organic electron transport layer(ETL)materials,the lowest unoccupied molecular orbital(LUMO)is 2.5-3.5 e V.Therefore,for the structure of inverted bottom cathode OLEDs,there is an extremely high electron injection barrier(approximately 2 e V at the ITO/ETL interface),which becomes the main factor hindering the realization of high-performance i OLEDs.Based on two injection theories,i.e.,Richardson-Schottky(RS)thermal injection and Fowler-Nordheim(FN)quantum tunneling,three methods have been introduced to achieve highperformance i OLEDs:(1)The most conventional method is barrier regulation,which involves the insertion of a low-workfunction material at the ITO/ETL interface to reduce the electron inje

关 键 词：倒置有机发光二极管 低功函数 界面偶极层 电子注入 掺杂 界面修饰 

分 类 号：TN383.1[电子电信—物理电子学]