Qiu Jingjing, Tang Lianqi, Xia Yingdong, Guo Jia, Xing Guichuan, Wang Fu, Dong Qingfeng, Chen Yonghua, Huang Wei
Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Jiangsu National Synergistic Innovation Center for Advanced Materials (SICAM) , Nanjing Tech University (NanjingTech) , 30 South Puzhu Road , Nanjing 211816 , P. R. China.
Institute of Applied Physics and Materials Engineering , University of Macau , Macau SAR 999078 , China.
J Phys Chem Lett. 2019 May 2;10(9):2101-2107. doi: 10.1021/acs.jpclett.9b00587. Epub 2019 Apr 16.
Although formamidinium lead iodide (FAPbI) perovskite shows excellent prospects in the field of optoelectronics, it is limited by the conversion of the black perovskite phase (α-FAPbI) to the yellow non-perovskite phase (δ-FAPbI). Here, we first introduce diamine cations [EDBE, 2,2-(ethylenedioxy)bis(ethylamine)] into FAPbI for stable and efficient near-infrared perovskite light-emitting diodes (NIR PeLEDs). By rationally regulating the α/δ phase, we have successfully prepared a NIR PeLED with an external quantum efficiency (EQE) of ≤11.40%. In addition, the perovskite film has excellent stability and does not undergo any significant change after being in air for 270 days. These results show that the introduction of EDBE reduces the formation energy of α-FAPbI perovskite and the hydrogen bonds formed between adjacent EDBE molecules increase the stability of the perovskite devices. This work could help guide the phase transition mechanism of FAPbI and further improve the performance of LEDs.
尽管甲脒碘化铅（FAPbI）钙钛矿在光电子领域展现出优异的前景，但它受到黑色钙钛矿相（α-FAPbI）向黄色非钙钛矿相（δ-FAPbI）转变的限制。在此，我们首次将二胺阳离子[EDBE，2,2-（乙二氧基）双（乙胺）]引入FAPbI中，以制备稳定且高效的近红外钙钛矿发光二极管（NIR PeLEDs）。通过合理调控α/δ相，我们成功制备出了外量子效率（EQE）≤11.40%的近红外钙钛矿发光二极管。此外，该钙钛矿薄膜具有出色的稳定性，在空气中放置270天后未发生任何显著变化。这些结果表明，EDBE的引入降低了α-FAPbI钙钛矿的形成能，并且相邻EDBE分子之间形成的氢键提高了钙钛矿器件的稳定性。这项工作有助于指导FAPbI的相变机制，并进一步提升发光二极管的性能。
