Near-unity blue-orange dual-emitting Mn-doped perovskite nanocrystals with metal alloying for efficient white light-emitting diodes

The tunable dual-color emitting Mn2+ doped CsPbCl3-xBrx nanocrystals (NCs) with near-unity photoluminescence quantum yield (PL QY) were synthesized through post-treatment of metal bromide at room temperature for fabrication of efficient warm white light-emitting diodes (WLEDs). Especially, the CdBr2 treated blue-orange emitting Mn doped NCs with various Mn/Pb molar feed ratios exhibit higher PL QY of 97% and longer Mn2+ PL lifetime of 0.9 ms. It is surprisingly found that the X-ray diffraction peak at 31.9 degrees is almost not changed with increasing Br composition, meaning formation of metal alloying due to incorporation of amount of divalent cation in NCs. The strong and stable Mn2+ PL at temperature ranging from 80 K to 360 K are revealed and the temperature-dependent energy transfer efficiencies in Mn2+ doped CsPbCl1.5Br1.5 NCs are obtained. The enhancement mechanism of Mn2+ PL QY was attributed to improved energy transfer from exciton to Mn2+ d-d transition and suppressed defect state density after post-treatment. The efficient warm WLEDs with color rendering index of 90 and luminous efficacy of 92 lm/W at 10 mA were fabricated by combining blue-orange dual-emitting Mn2+ doped CsPbCl(3)xBrx@SiO2 and green emissive CsPbBr3@SiO2 NCs with violet GaN chips. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

Tunable dual-color emitting Mn2+ doped CsPbCl3-xBrx nanocrystals with near-unity photoluminescence quantum yield were successfully synthesized through post-treatment of metal bromide for efficient warm white light-emitting diodes fabrication. The enhanced Mn2+ PL quantum yield was attributed to improved energy transfer and suppressed defect state density, resulting in stable Mn2+ PL emission and energy transfer efficiencies at different temperatures. High-efficiency warm white light-emitting diodes with a color rendering index of 90 and luminous efficacy of 92 lm/W were achieved by combining blue-orange dual-emitting Mn2+ doped CsPbCl(3)xBrx@SiO2 and green emissive CsPbBr3@SiO2 nanocrystals with violet GaN chips.