【摘 要】
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The application of polymers to replace oleylamine (OLA) and oleic acid (CA) as ligands for perovskite nanocrystals is an effective strategy to improve their sta
【机 构】
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Physical Chemistry, Technische Universit(a)t Dresden, Zellescher Weg 19, 01069 Dresden, Germany;Depa
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The application of polymers to replace oleylamine (OLA) and oleic acid (CA) as ligands for perovskite nanocrystals is an effective strategy to improve their stability and durability especially for the solution-based processing.Herein,we report a mechanosynthesis of lead bromide perovskite nanoparticles (NPs) stabilized by partially hydrolyzed poly(methyl methacrylate) (h-PMMA) and high-molecular-weight highly-branched poly(ethylenimine) (PEI-25K).The es-synthesized NP solutions exhibited green emission centered at 516 nm,possessing a narrow full-width at haft-maximum of 17 nm and as high photoluminescence quantum yield (PL QY) as 85％,while showing excellent durability and resistance to polar solvents,e.g.,methanol.The colloids of polymer-stabilized NPs were directly processable to form stable and strongly-emitting thin films and solids,making them attractive as gain media.Furthermore,the roles of h-PMMA and PEI-25K in the grinding process were studied in depth.The h-PMMA can form micelles in the grinding solvent of dichloromethane to act as size-regulating templates for the growth of NPs.The PEI-25K with large amounts of amino groups induced significant enrichment of PbBr2 in the reaction mixture,which in tum caused the formation of CsPb-2Br5-mPbBr2 and CsPbBr3-Cs4PbBre-nCsBr NPs.The presence of CsPbBr3-Cs4PbBre-nCsBr NPs was responsible for the high PL QY,as the Cs4PbBre phase with a wide energy bandgap can passivate the surface defects of the CsPbBr3 phase.This work describes a direct and facile mechanosynthesis of polymer-coordinated perovskite NPs and promotes in-depth understanding of the formation and phase conversion for perovskite NPs in the gdnding process.
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