郑州大学宋继中团队报道了匹配电子输运材料实现高效稳定的钙钛矿量子点发光二极管。相关研究成果发表在2024年7月27日出版的国际学术期刊《德国应用化学》。

该文中，研究人员报道了具有吡啶和三嗪的强吸电子部分的2,4,6-三（3'-（吡啶-3-基）联苯-3-基）-1,3,5-三嗪（TmPPPyTz，3P），以调节P-QLED的性能s。与常用的1,3,5-三（1-苯基-1H-苯并咪唑-2-基）苯（TPBi）相比，3P中的吡啶与钙钛矿有很强的相互作用，可以有效抑制量子点表面·Pb²⁺缺陷引起的界面非辐射复合。

3P具有深的最高占据分子轨道（HOMO）（增强空穴阻挡性能）、匹配的最低未占据分子轨道和优异的电子迁移率（增强电子输运性能），实现了载流子平衡并最大限度地提高了激子复合。此外，·3P的高热阻明显提高了量子点在变温、连续紫外照射和电场激发下的稳定性。

结果发现，使用3P作为ETM的P-QLEDs取得了出色的性能，在初始亮度为100cdm^-2时，最大EQE为30.2%·，工作寿命T₅₀为3220小时，分别比对照设备提高了151%和约11倍（EQE=20%，T₅₀=297小时）。

研究结果为从选择性ETM的角度构建高效稳定的P-QLEDs提供了新的思路。

附：英文原文

Title: Matched Electron Transport Materials Enabling Efficient and Stable Perovskite Quantum Dot-based Light-Emitting Diodes

Author: Jindi Wang, Mingyang Li, Bo Cai, Hongdan Ren, Wenxuan Fan, Leimeng Xu, Jisong Yao, Shalong Wang, Jizhong Song

Issue&Volume: 2024-07-27

Abstract: Here, we report 2,4,6-Tris(3'-(pyridine-3-yl) biphenyl-3-yl)-1,3,5-triazine (TmPPPyTz, 3P) with strong electron-withdrawing moieties of pyridine and triazine to modulate the performance of P-QLEDs. Compared with commonly used 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi), the pyridine in 3P have a strong interaction with perovskites, which can effectively suppress the interface non-radiative recombination caused by the·Pb2+ defects on the surface of QDs. In addition, 3P have deep highest occupied molecular orbital (HOMO) (enhancing hole-blocking properties), matched lowest unoccupied molecular orbital (LUMO) and excellent electron mobility (enhancing electron transport properties), realizing the carrier balance and maximizing the exciton recombination. Furthermore, high thermal resistance of·3P obviously improves the stability of QDs under variable temperature, continuous UV illumination, and electric field excitation. Resultantly, the P-QLEDs using the 3P as ETM achieved an outstanding performance with a champion EQE of 30.2%·and an operational lifetime T50·of 3220 hours at an initial luminance of 100 cd m-2, which is 151% and about 11-fold improvement compared to control devices (EQE = 20%, T50 = 297 hours), respectively. These results provide a new concept for constructing the efficient and stable P-QLEDs from the perspective of selective ETM.

DOI: 10.1002/anie.202410689

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202410689