Metal halide perovskite generates extremely sharp emission peak and high luminescence quantum yield, enabling it to be a promising candidate as the new generation of emitting materials for displays. However, the development of perovskite LEDs is impeded by their fast carriers diffusion and poor stability in air. Herein, quasi 2D CsPbBr3 quantum wells homogeneously surrounded by inorganic crystalline Cs4PbBr6 of large bandgap are grown. The centralization of carriers in nanoregion facilitates radiative recombination and brings much enhanced luminescence quantum yield. The external quantum efficiency and luminescence intensity of the LEDs based on this nanocomposite are one order of magnitude higher than the conventional low dimensional perovskite. Meanwhile, the use of inorganic nanocomposite materials brings much improved device operation lifetime under constant electrical field.
By using bidentate 2,2’-Iminodibenzoic acid as conductive ligand, we preapared CsPbI3 NCs based high efficiency red color light emitting diode. The passivated NCs enabled us to realize red light emitting diodes (LEDs) with 5.02% external quantum efficiency and 748 cd/m2 luminance, which is the higest efficiency realized at that time.
1. Yuequn Shang, Gang Li, Weimin Liu, and Zhijun Ning*, Quasi 2D Inorganic CsPbBr3 Perovskite for Efficient and Stable Light-Emitting Diodes, Adv. Funct. Mater., 2018, 1801193
2. Jun Pan , Yuequn Shang, Jun Yin, Michele De Bastiani, Wei Peng, Ibrahim Dursun, Lutfan Sinatra, Ahmed M. El-Zohry, Mohamed N. Hedhili, Abdul-Hamid Emwas, Omar F. Mohammed, Zhijun Ning*, and Osman M. Bakr*, Bidentate Ligand-Passivated CsPbI3 Perovskite Nanocrystals for Stable Near-Unity Photoluminescence Quantum Yield and Efficient Red Light-Emitting Diodes. J. Am. Chem. Soc., 2018, 140, 562–565.