Bidentate Ligand-Passivated CsPbI3 Perovskite Nanocrystals for Stable Near-Unity Photoluminescence Quantum Yield and Efficient Red Light-Emitting Diodes

• Published in: Journal of the American Chemical Society Vol. 140; no. 2; pp. 562 - 565
• Main Authors: Pan, Jun, Shang, Yuequn, Yin, Jun, De Bastiani, Michele, Peng, Wei, Dursun, Ibrahim, Sinatra, Lutfan, El-Zohry, Ahmed M, Hedhili, Mohamed N, Emwas, Abdul-Hamid, Mohammed, Omar F, Ning, Zhijun, Bakr, Osman M
• Format: Journal Article
• Language: English
• Published: American Chemical Society 17-01-2018
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.7b10647

Although halide perovskite nanocrystals (NCs) are promising materials for optoelectronic devices, they suffer severely from chemical and phase instabilities. Moreover, the common capping ligands like oleic acid and oleylamine that encapsulate the NCs will form an insulating layer, precluding their utility in optoelectronic devices. To overcome these limitations, we develop a postsynthesis passivation process for CsPbI3 NCs by using a bidentate ligand, namely 2,2′-iminodibenzoic acid. Our passivated NCs exhibit narrow red photoluminescence with exceptional quantum yield (close to unity) and substantially improved stability. The passivated NCs enabled us to realize red light-emitting diodes (LEDs) with 5.02% external quantum efficiency and 748 cd/m2 luminance, surpassing by far LEDs made from the nonpassivated NCs.