The zero-dimensional perovskite composite Cs_(4)PbBr_(6)/CsPbBr_(3) has attracted significant attention for its remarkable photoluminescence(PL),which remains highly effective even in solid state.This work presents a ...The zero-dimensional perovskite composite Cs_(4)PbBr_(6)/CsPbBr_(3) has attracted significant attention for its remarkable photoluminescence(PL),which remains highly effective even in solid state.This work presents a detailed analysis of the steady-state and time-resolved PL(TRPL)behavior of millimeter-scale Cs_(4)PbBr_(6)/CsPbBr_(3) crystals over a temperature range of 80 to 360 K,which covers exciton binding en-ergy,phonon energy,and PL peak energy shifting with increasing temperature.According to the results,Cs_(4)PbBr_(6)/CsPbBr_(3) exhibits high exciton binding energy and phonon energy,with calculated values of 358.7 and 94.8 meV,respectively.Specifically,when the temperature is below~235 K,thermal expan-sion dominates to influence the TRPL and peak energy,whereas electron-phonon interaction becomes the dominant factor as temperature rises from 235 to 325 K.It is found that Cs_(4)PbBr_(6)/CsPbBr_(3) has a PL behavior similar to CsPbBr_(3),and characterization and TRPL results demonstrate that nanometer-scale CsPbBr_(3) crystals embed in the Cs_(4)PbBr_(6) bulk matrix.Meanwhile,a white light-emitting diode(WLED)device based on Cs_(4)PbBr_(6)/CsPbBr_(3) with luminous efficiency of 64.56 Im/W is fabricated,and its color coordinate is measured as(0.34,0.31)under 20 mA,which is in close proximity to the standard white color coordinate.Moreover,the color gamut of the device is measured as 128.66%of the National Televi-sion Systems Committee(NTSC).The WLED electroluminescence(EL)spectra show high Correlated Color Temperature(CCT)stability for the working current varying from 5 to 100 mA,and after continuous oper-ation for 12 h,the EL intensity decreases and stabilizes at~70%of the initial EL intensity.These findings suggest that Cs_(4)PbBr_(6)/CsPbBr_(3) crystals are a promising candidate for WLEDs.展开更多
基金Heilongjiang Provincial Key Laboratory of Micro-nano Sensitive Devices and Systems(Heilongjiang)and Cultivation project of double first-class initiative discipline by Heilongjiang Province(No.LJGXCG2022–061)M.C.acknowledges support from the European Research Council(ERC)under the European Union's Horizon 2020 research and innovation program"NANOLED ERC-2019-STG Grant agreement No.851794".
文摘The zero-dimensional perovskite composite Cs_(4)PbBr_(6)/CsPbBr_(3) has attracted significant attention for its remarkable photoluminescence(PL),which remains highly effective even in solid state.This work presents a detailed analysis of the steady-state and time-resolved PL(TRPL)behavior of millimeter-scale Cs_(4)PbBr_(6)/CsPbBr_(3) crystals over a temperature range of 80 to 360 K,which covers exciton binding en-ergy,phonon energy,and PL peak energy shifting with increasing temperature.According to the results,Cs_(4)PbBr_(6)/CsPbBr_(3) exhibits high exciton binding energy and phonon energy,with calculated values of 358.7 and 94.8 meV,respectively.Specifically,when the temperature is below~235 K,thermal expan-sion dominates to influence the TRPL and peak energy,whereas electron-phonon interaction becomes the dominant factor as temperature rises from 235 to 325 K.It is found that Cs_(4)PbBr_(6)/CsPbBr_(3) has a PL behavior similar to CsPbBr_(3),and characterization and TRPL results demonstrate that nanometer-scale CsPbBr_(3) crystals embed in the Cs_(4)PbBr_(6) bulk matrix.Meanwhile,a white light-emitting diode(WLED)device based on Cs_(4)PbBr_(6)/CsPbBr_(3) with luminous efficiency of 64.56 Im/W is fabricated,and its color coordinate is measured as(0.34,0.31)under 20 mA,which is in close proximity to the standard white color coordinate.Moreover,the color gamut of the device is measured as 128.66%of the National Televi-sion Systems Committee(NTSC).The WLED electroluminescence(EL)spectra show high Correlated Color Temperature(CCT)stability for the working current varying from 5 to 100 mA,and after continuous oper-ation for 12 h,the EL intensity decreases and stabilizes at~70%of the initial EL intensity.These findings suggest that Cs_(4)PbBr_(6)/CsPbBr_(3) crystals are a promising candidate for WLEDs.
