Wang Chenhui, Han Dengbao, Wang Junhui, Yang Yingguo, Liu Xinyue, Huang Sheng, Zhang Xin, Chang Shuai, Wu Kaifeng, Zhong Haizheng
MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, School of Materials Science & Engineering, Beijing Institute of Technology, 100081, Beijing, China.
State Key Laboratory of Molecular Reaction Dynamics and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 116023, Dalian, China.
Nat Commun. 2020 Dec 22;11(1):6428. doi: 10.1038/s41467-020-20163-7.
In the field of perovskite light-emitting diodes (PeLEDs), the performance of blue emissive electroluminescence devices lags behind the other counterparts due to the lack of fabrication methodology. Herein, we demonstrate the in situ fabrication of CsPbClBr nanocrystal films by using mixed ligands of 2-phenylethanamine bromide (PEABr) and 3,3-diphenylpropylamine bromide (DPPABr). PEABr dominates the formation of quasi-two-dimensional perovskites with small-n domains, while DPPABr induces the formation of large-n domains. Strong blue emission at 470 nm with a photoluminescence quantum yield up to 60% was obtained by mixing the two ligands due to the formation of a narrower quantum-well width distribution. Based on such films, efficient blue PeLEDs with a maximum external quantum efficiency of 8.8% were achieved at 473 nm. Furthermore, we illustrate that the use of dual-ligand with respective tendency of forming small-n and large-n domains is a versatile strategy to achieve narrow quantum-well width distribution for photoluminescence enhancement.
在钙钛矿发光二极管（PeLEDs）领域，由于缺乏制造方法，蓝色发光电致发光器件的性能落后于其他同类器件。在此，我们展示了通过使用溴化2-苯乙胺（PEABr）和溴化3,3-二苯基丙胺（DPPABr）的混合配体原位制备CsPbClBr纳米晶薄膜的方法。PEABr主导了具有小n域的准二维钙钛矿的形成，而DPPABr诱导了大n域的形成。由于形成了更窄的量子阱宽度分布，通过混合这两种配体获得了在470 nm处的强蓝光发射，光致发光量子产率高达60%。基于此类薄膜，在473 nm处实现了最大外量子效率为8.8%的高效蓝色PeLEDs。此外，我们表明使用具有形成小n域和大n域各自倾向的双配体是实现窄量子阱宽度分布以增强光致发光的通用策略。
