All-inorganic cesium lead halide based perovskite nanocrystals(PNCs)exhibit promising optoelectronic properties,but their poor stability and anion exchange reaction limit their broad commercial applications.Herein,we ...All-inorganic cesium lead halide based perovskite nanocrystals(PNCs)exhibit promising optoelectronic properties,but their poor stability and anion exchange reaction limit their broad commercial applications.Herein,we demonstrated the successful synthesis of blue-green-red emitting CsPbX_(3)(X=Cl/Br,Br,and Br/I)PNCs via hot injection method,followed by silica-coating and embedding in poly(methylmethacrylate)(PMMA)matrix.The photoluminescence(PL)spectra of SiO_(2)/PMMA-coated PNCs can be tuned continuously by regulating precursor composition ratio,from blue(CsPb(Cl_(0.5)/Br_(0.5))_(3);460 nm)to red(CsPb(Br_(0.4)/I_(0.6))_(3)via green(CsPbBr_(3);519 nm).The PNCs composite films exhibit improved stability(thermal-,moisture-,and photo-stability)because of the barrier formed by Si0_(2)/PMMA coating and also displayed exceptional photoluminescent quantum yield(PLQY of blue,green,and red-emitting Si0_(2)/PMMA coated PNCs are 37%,86%,and 71%,respectively)with longer lifetimes inhibiting anion exchange.Eventually,the PNCs-encapsulated Si0_(2)/PMMA composite films were integrated into the UV LED chip as down-converting materials to construct a prototype white-peLED unit.The designed white-peLED unit demonstrated bright white light generating CIE coordinates(0.349,0.350),a luminous efficiency(LE)of 39.2%and a color rendering index(CRI)of 84.7.The wide color gamut of 121.47%of NTSC and 98.56%of Rec.2020 is also achieved with the built w-LED system.Therefore,the results demonstrated that CsPbX_(3)(X=Cl/Br,Br,and Br/I)PNCs@SiO_(2)/PMMA composite films can be employed as efficient UV to visible color conversion materials for white-LEDs and backlighting.展开更多
基金the Space Core Technology Development Program(No.2017M1A3A3A02016782).
文摘All-inorganic cesium lead halide based perovskite nanocrystals(PNCs)exhibit promising optoelectronic properties,but their poor stability and anion exchange reaction limit their broad commercial applications.Herein,we demonstrated the successful synthesis of blue-green-red emitting CsPbX_(3)(X=Cl/Br,Br,and Br/I)PNCs via hot injection method,followed by silica-coating and embedding in poly(methylmethacrylate)(PMMA)matrix.The photoluminescence(PL)spectra of SiO_(2)/PMMA-coated PNCs can be tuned continuously by regulating precursor composition ratio,from blue(CsPb(Cl_(0.5)/Br_(0.5))_(3);460 nm)to red(CsPb(Br_(0.4)/I_(0.6))_(3)via green(CsPbBr_(3);519 nm).The PNCs composite films exhibit improved stability(thermal-,moisture-,and photo-stability)because of the barrier formed by Si0_(2)/PMMA coating and also displayed exceptional photoluminescent quantum yield(PLQY of blue,green,and red-emitting Si0_(2)/PMMA coated PNCs are 37%,86%,and 71%,respectively)with longer lifetimes inhibiting anion exchange.Eventually,the PNCs-encapsulated Si0_(2)/PMMA composite films were integrated into the UV LED chip as down-converting materials to construct a prototype white-peLED unit.The designed white-peLED unit demonstrated bright white light generating CIE coordinates(0.349,0.350),a luminous efficiency(LE)of 39.2%and a color rendering index(CRI)of 84.7.The wide color gamut of 121.47%of NTSC and 98.56%of Rec.2020 is also achieved with the built w-LED system.Therefore,the results demonstrated that CsPbX_(3)(X=Cl/Br,Br,and Br/I)PNCs@SiO_(2)/PMMA composite films can be employed as efficient UV to visible color conversion materials for white-LEDs and backlighting.
