CsPbBr_(3)@MIL-53纳米复合荧光粉的合成、性能及其白光LEDs应用

CsPbBr_(3)@MIL-53 Nanocomposite Phosphors:Synthesis,Properties and Applications in White LEDs

全无机钙钛矿(CsPbX3,X=Cl,Br,I)纳米晶因其卓越的光电性能被广泛应用于光电子器件领域,但稳定性问题仍然是制约其商业化发展的主要因素之一。基于此,本研究以提高CsPbBr_(3)纳米晶的稳定性和固态发光性能为研究目标,选用具有优异疏水性能的多孔MIL-53(Al)金属有机框架(MOFs)作为封装基质,通过热注射工艺在MIL-53(Al)孔道内原位限域生长CsPbBr_(3)纳米晶,成功制备了优异发光性能和稳定性的CsPbBr_(3)@MIL-53纳米复合荧光粉。MIL-53通过包含的苯环和有机配体与CsPbBr_(3)纳米晶螯合,将其稳固地锚定在孔道内,既保护了CsPbBr_(3)纳米晶免受外界环境的影响,又有效防止了纳米晶之间的聚集,从而避免了固态荧光猝灭。此外,MIL-53中的COO-官能团与CsPbBr_(3)纳米晶表面未配对的Pb2+结合,钝化了其表面的缺陷,抑制了载流子的非辐射复合。MIL-53包含的苯环及有机长链又赋予了纳米复合荧光粉出色的疏水性能。这些因素的协同作用显著提升了CsPbBr_(3)@MIL-53纳米复合荧光粉的光学性能和水稳定性,其荧光量子产率(Photoluminescence Quantum Yield,PLQY)为75.4%,是固态CsPbBr_(3)纳米晶粉体(33.2%)的2.3倍。将CsPbBr_(3)@MIL-53纳米复合荧光粉完全浸泡在水中10h,其荧光强度仍能维持初始值的75.6%。最后,将绿光发射的CsPbBr_(3)@MIL-53纳米复合荧光粉应用于白光发光二极管(LightEmittingDiodes,LEDs)器件,实现了126%NTSC和85%Rec.2020的宽色域覆盖面积,表明其在显示器件领域具有优异的应用前景。

The all-inorganic CsPbX3(X=Cl,Br,I)perovskite nanocrystals have been widely applied in optoelectronic devices due to their excellent optoelectronic properties.However,their poor stability remains one of the main factors restricting their commercial development.This research focuses on improving the stability and solid-state luminescence performance of CsPbBr_(3)nanocrystals.The porous MIL-53(Al)metal-organic frameworks(MOFs)with outstanding hydrophobic properties was chosen as the encapsulation matrix.CsPbBr_(3)nanocrystals were grown in situ within the MIL-53(Al)channels by using a thermal injection process to successfully synthesize CsPbBr_(3)@MIL-53 nanocomposite phosphors with outstanding solid-state luminescence performance and high stability.MIL-53 chelates with CsPbBr_(3)nanocrystals through benzene rings and organic ligands,firmly anchoring nanocrystals in the pores.This not only protects the CsPbBr_(3)nanocrystals from external environmental influences but also effectively prevents aggregation between nanocrystals,thereby avoiding quenching of solid-state fluorescence.Additionally,the COO-functional groups in MIL-53 bind with the unpaired Pb2+on the surface of CsPbBr_(3)nanocrystals,passivating the surface defects and suppressing non-radiative carrier recombination.Furthermore,the contained benzene rings and organic long chains endow the nanocomposite phosphors with excellent hydrophobic properties.The synergistic effect of these factors significantly enhances the optical performance and water stability of CsPbBr_(3)@MIL-53 nanocomposite phosphors.As a result,photoluminescence quantum yield(PLQY)of CsPbBr_(3)@MIL-53 nanocomposite phosphors reaches 75.4%,which is 2.3 times of that of solid-state CsPbBr_(3)nanocrystal powders(33.2%).Even after being completely immersed in water for 10 h,its fluorescence intensity can still maintain 75.6%of the initial value.Finally,the green-emitting CsPbBr_(3)@MIL-53 nanocomposite phosphors were applied to white LED devices,achieving a wide-color-gamut coverage area of 126%NTSC and 85%Rec.2020,which demonstrates its application prospects in wide-color-gamut display devices.