General Mild Reaction Creates Highly Luminescent Organic-Ligand-Lacking Halide Perovskite Nanocrystals for Efficient Light-Emitting Diodes.
KAUST DepartmentMaterials Science and Engineering Program
KAUST Catalysis Center (KCC)
Physical Sciences and Engineering (PSE) Division
Embargo End Date2020-08-31
Permanent link to this recordhttp://hdl.handle.net/10754/656815
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AbstractThe 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 (PL) 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 light-emitting diodes (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.
SponsorsThis work was supported by the National Natural ScienceFoundation of China (Grant nos. 11874275, 11574225, and U1805252), a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), a project supported by CAS 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.
PublisherAmerican Chemical Society (ACS)