作者: | Bin-Bin Zhang1, Shuai Yuan2, Ju-Ping Ma1, Yang Zhou1, Jingshan Hou3, Xueyuan Chen4, Wei Zheng4, Huaibin Shen5, Xue-Chun Wang2, Baoquan Sun2, Osman M. Bakr6, Liang-Sheng Liao2*, and Hong-Tao Sun1*
|
单位: | 1College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China, Jiangsu 2Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM) & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, China 3School of Materials Science and Engineering, Shanghai Institute of Technology, Shanghai 201418, China 4CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China 5Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004, China 6Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabi
|
摘要: | The presence of labile bulky insulating hydrocarbon ligands in halide perovskite nanocrystals (NCs) passivates surface traps, but concurrently makes charge transport difficult in optoelectronic devices. Early efforts routinely rely on the replacement of long-chain ligands with short-chain cousins, leading to notable changes in NC’s sizes and photophysical properties and thus making it hard to obtain devices with nearly designed emissions. Here we report a general solution-phase ligand-exchange strategy to produce organic-ligand-lacking halide perovskite NCs with high photoluminescence quantum yields and good stability in ambient air. We demonstrate that the ligand exchange can be achieved by a well-controlled mild reaction of thionyl halide with the carboxylic and amine groups on the NC’s surface, resulting in nearly dry NCs with well passivated surfaces and almost unaltered emission characteristics. Consequently, we achieve exceptionally high-performance blue perovskite NC LEDs with an external quantum efficiency of up to 1.35% and an extremely narrow full width at half maximum of 14.6 nm. Our work provides a systematic framework for preparing high-quality organic-ligand-lacking perovskite NC inks that can be directly cast as films featuring effective charge transport, thereby providing the foundation for further development of a wide range of efficient perovskite optoelectronic devices.
|