Yi Yuan-Qiu-Qiang, Su Fuyan, Xu Wenya, Zhang Qing, Zhang Shuo, Xie Liming, Su Wenming, Cui Zheng, Luscombe Christine K
Printable Electronics Research Center, Division of Nano-Devices Research, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, Jiangsu 215123, China.
Pi-Conjugated Polymers Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan.
ACS Nano. 2024 Jun 18;18(24):15915-15924. doi: 10.1021/acsnano.4c03458. Epub 2024 Jun 4.
Considering the increasing demand for high-resolution light-emitting diodes (LEDs), it is important that direct fine patterning technologies for LEDs be developed, especially for quantum-dot LEDs (QLEDs). Traditionally, the patterning of QLEDs relies on resin-based photolithography techniques, requiring multiple steps and causing performance deterioration. Nondestructive direct patterning may provide an easy and stepwise method to achieve fine-pixelated units in QLEDs. In this study, two isomeric tridentate cross-linkers (X8/X9) are presented and can be blended into the hole transport layer (HTL) and the emissive layer (EML) of QLEDs. Because of their photosensitivity, the in situ cross-linking process can be efficiently triggered by ultraviolet irradiation, affording high solvent resistance and nondestructive direct patterning of the layers. Red QLEDs using the cross-linked HTL demonstrate an impressive external quantum efficiency of up to 22.45%. Through lithographic patterning enabled by X9, line patterns of HTL and EML films exhibit widths as narrow as 2 and 4 μm, respectively. Leveraging the patterned HTL and EML, we show the successful fabrication of pixelated QLED devices with an area size of 3 × 3 mm, alongside the successful production of dual-color pixelated QLED devices. These findings showcase the promising potential of direct patterning facilitated by engineered cross-linkers for the cost-effective fabrication of pixelated QLED displays.
考虑到对高分辨率发光二极管（LED）的需求不断增加，开发用于LED的直接精细图案化技术非常重要，特别是对于量子点发光二极管（QLED）。传统上QLED的图案化依赖于基于树脂的光刻技术，需要多个步骤并导致性能下降。非破坏性直接图案化可以提供一种简单且逐步的方法来实现QLED中的精细像素化单元。在本研究中，提出了两种异构三齿交联剂（X8/X9），它们可以混入QLED的空穴传输层（HTL）和发光层（EML）中。由于它们的光敏性，原位交联过程可以通过紫外线照射有效地触发，从而提供高耐溶剂性和各层的非破坏性直接图案化。使用交联HTL的红色QLED表现出高达22.45%的令人印象深刻的外量子效率。通过由X9实现的光刻图案化，HTL和EML薄膜的线条图案分别显示出窄至2μm和4μm的宽度。利用图案化的HTL和EML，我们展示了成功制造面积为3×3mm的像素化QLED器件，以及成功生产双色像素化QLED器件。这些发现展示了工程化交联剂促进的直接图案化在经济高效地制造像素化QLED显示器方面的广阔潜力。
