Author Affiliations
Abstract
1 Institute of Nanoscience and Applications, and Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China
2 Key Laboratory of Energy Conversion and Storage Technologies (Southern University of Science and Technology), Ministry of Education, Guangdong University Key Laboratory for Advanced Quantum Dot Displays and Lighting, and Shenzhen Key Laboratory for Advanced Quantum Dot Displays and Lighting, Southern University of Science and Technology, Shenzhen 518055, China
3 Institute of Advanced Displays and Imaging, Henan Academy of Sciences, Zhengzhou 450046, China
The performance of inverted quantum-dot light-emitting diodes (QLEDs) based on solution-processed hole transport layers (HTLs) has been limited by the solvent-induced damage to the quantum dot (QD) layer during the spin-coating of the HTL. The lack of compatibility between the HTL's solvent and the QD layer results in an uneven surface, which negatively impacts the overall device performance. In this work, we develop a novel method to solve this problem by modifying the QD film with 1,8-diaminooctane to improve the resistance of the QD layer for the HTL’s solvent. The uniform QD layer leads the inverted red QLED device to achieve a low turn-on voltage of 1.8 V, a high maximum luminance of 105 500 cd/m2, and a remarkable maximum external quantum efficiency of 13.34%. This approach releases the considerable potential of HTL materials selection and offers a promising avenue for the development of high-performance inverted QLEDs.
quantum dots quantum-dot light-emitting diodes inverted structure ligand treatment Journal of Semiconductors
2023, 44(9): 092603
1 中国科学院 理化技术研究所, 北京 100190
2 中国科学院大学, 北京 100049
在有机发光二极管(OLEDs) 30多年的发展过程中, 器件结构设计和功能材料开发是实现器件高效率发光的关键。倒置结构器件被认为是实现OLEDs器件高效率、长寿命的一种可行方案。但倒置器件以ITO为阴极造成了器件电子注入势垒过大, 限制了倒置器件的进一步发展。本文以实现倒置器件电子注入原理的不同, 分别介绍了n型掺杂、偶极层修饰和隧穿注入等方法在提高ITO阴极电子注入性能的相关研究工作。最后, 对提高倒置器件电子注入性能的3种不同策略进行了总结和展望。
有机发光二极管 倒置结构 电子注入 n型掺杂 偶极层 organic light-emitting diodes inverted structure electron injection n-type doping dipole layer
华南理工大学 发光材料与器件国家重点实验室, 广东 广州 510641
设计了环己基苯与十八烯的双溶剂量子点墨水体系, 研究了具有CdSe@ZnS/ZnS核/壳结构的绿光量子点(QDs)成膜规律及其发光特性。设计的高沸点、低表面张力的十八烯和低沸点、高表面张力的环己基苯所组成的双溶剂墨水体系增强了马兰戈尼流, 减弱了量子点在像素坑边缘的沉积, 实现了在像素坑中制备表面平整的量子点薄膜。研制的分辨率为240 PPI的倒置结构顶发射绿光量子点阵列发光器件启亮电压2.7 V, 最高亮度132 510 cd/m2, 最大外量子效率14.0%, 为采用喷墨打印工艺制备高性能量子点电致发光点阵器件提供了借鉴。
喷墨打印 墨水调控 量子点薄膜 倒置结构 量子点发光二极管 ink jet printing ink formulation quantum dot film inverted structure quantum dot light-emitting diodes
合肥工业大学 光电技术研究院,特种显示技术国家工程实验室, 省部共建现代显示技术国家重点实验室(培育基地), 合肥 230009
基于2,7-二辛基［1］苯并噻吩并［3,2-b］苯并噻吩(C8-BTBT)与无机钙钛矿CsPbBr3 量子点构成复合发光层, 采用倒置QLED器件结构(ITO/ZnO/EML/CBP/MoO3/Al), 研究了氧化锌电子传输层的镁离子掺杂工艺对发光层荧光量子效率及界面稳定性的影响规律和机制。镁离子掺杂可以在一定范围内线性调控电子传输层的光学带隙, 同时有效改善薄膜的表面形貌, 从而提高与发光层之间的界面质量。实验发现, 相对于未掺杂的ZnO薄膜, Mg0.09Zn0.91O薄膜的表面粗糙度和表面能显著下降, 光学带隙则提高了0.2 eV, 相应的以电子漂移为主的电导率显著下降。进一步通过调控复合发光层中的主客体比例, 可以调节空穴注入比, 改善载流子传输的平衡性。采用Mg0.09Zn0.91O薄膜作为电子传输层的主客体复合发光层具有更高的荧光量子效率和PL荧光寿命。研究为开发相应的倒置结构电致发光器件提供了坚实的实验依据。
倒置结构 2,7-二辛基［1］苯并噻吩并［3,2-b］苯并噻吩 inverted structure MgxZn1-xO MgxZn1-xO 2,7-dioctyl［1］benzothieno［3,2-b］benzothiophene CsPbBr3 CsPbBr3
Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China
The work function (WF) of indium-tin-oxide (ITO) substrates plays an important role on the inverted organic photovoltaic device performance. And electrode engineering has been a useful method to facilitate carrier extraction or charge collection to enhance organic photovoltaic (OPV) performance. By using self-assembly technique, we have deposited poly(dimethyl diallylammonium chloride) (PDDA) layers onto ITO coated glass substrates. The results indicate that the surface WF of ITO is reduced by about 0.3 eV after PDDA modification, which is attributed to the modulation in electron affinity. In addition, the surface roughness of ITO substrate became smaller after PDDA modification. These modified ITO substrates can be applied to fabricate inverted OPVs, in which ITO works as the cathode to collect electrons. As a result, the photovoltaic performance of inverted OPV is substantially improved, mainly reflecting on the increase of short circuit current density.
organic photovoltaic (OPV) organic photovoltaic (OPV) indium tin oxide (ITO) indium tin oxide (ITO) inverted structure inverted structure surface modification surface modification work function (WF) work function (WF) Frontiers of Optoelectronics
2015, 8(3): 269
