Cai Wanqing, Chen Ziming, Li Zhenchao, Yan Lei, Zhang Donglian, Liu Linlin, Xu Qing-Hua, Ma Yuguang, Huang Fei, Yip Hin-Lap, Cao Yong
State Key Laboratory of Luminescent Materials and Devices, Institute of Polymer Optoelectronic Materials and Devices, School of Materials Science and Engineering , South China University of Technology , 381 Wushan Road , Guangzhou 510640 , P. R. China.
Department of Chemistry , National University of Singapore , 117543 Singapore.
ACS Appl Mater Interfaces. 2018 Dec 12;10(49):42564-42572. doi: 10.1021/acsami.8b13418. Epub 2018 Nov 29.
In the past few years, substantial progress has been made in perovskite light-emitting devices. Both pure green and infrared thin-film perovskite light-emitting devices with external quantum efficiency over 20% have been successfully achieved. However, pure-red and blue thin-film perovskite light-emitting diodes still suffer from inferior efficiency. Therefore, the development of efficient and stable thin-film perovskite light-emitting diodes with pure-red and blue emissions is urgently needed for possible applications as a new display technology and solid-state lighting. Here, we demonstrate an efficient light-emitting diode with pure-red emission based on polymer-assisted in situ growth of high-quality all-inorganic CsPbBrI perovskite nanocrystal films with homogenous distribution of nanocrystals with size 20-30 nm. With this method, we can dramatically reduce the formation temperature of CsPbBrI and stabilize its perovskite phase. Eventually, we successfully demonstrate a pure-red-emission perovskite light-emitting diode with a high external quantum efficiency of 6.55% and luminance of 338 cd/m. Furthermore, the device obtains an ultralow turn-on voltage of 1.5 V and a half-lifetime of over 0.5 h at a high initial luminance of 300 cd/m.
在过去几年中，钙钛矿发光器件取得了显著进展。已成功实现了外量子效率超过20%的纯绿色和红外薄膜钙钛矿发光器件。然而，纯红色和蓝色薄膜钙钛矿发光二极管的效率仍然较低。因此，迫切需要开发高效且稳定的具有纯红色和蓝色发射的薄膜钙钛矿发光二极管，以作为一种新的显示技术和固态照明实现可能的应用。在此，我们展示了一种基于聚合物辅助原位生长高质量全无机CsPbBrI钙钛矿纳米晶薄膜的高效纯红色发光二极管，该薄膜中纳米晶体尺寸为20 - 30 nm且分布均匀。通过这种方法，我们可以大幅降低CsPbBrI的形成温度并稳定其钙钛矿相。最终，我们成功展示了一种纯红色发射的钙钛矿发光二极管，其外量子效率高达6.55%，亮度为338 cd/m²。此外，该器件在300 cd/m²的高初始亮度下具有1.5 V的超低开启电压和超过0.5 h的半衰期。
