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<p>Organic–inorganic hybridized MAPbBr<sub>3</sub> (CH<sub>3</sub>NH<sub>3</sub><sup>+</sup> = MA) perovskite quantum dots (PQDs) are promising photoelectronic materials for lighting and display applications. However, the toxicity of lead and their low stability greatly hinder their practical applications. A-site and B-site doping can increase fluorescence intensity, reduce Pb toxicity, and improve the stability. Herein, the effects of A-site and B-site doping on the crystal structure and optical properties of MAPbBr<sub>3</sub> PQDs are investigated. First, the MAPbBr<sub>3</sub> PQDs are A-site doped by dimethylammonium (DMA<sup>+</sup>) to methylammonium (MA<sup>+</sup>). Second, the Pb<sup>2+</sup> ions in MA<sub>0.5</sub>DMA<sub>0.5</sub>PbBr<sub>3</sub> PQDs are B-site doped by Mn<sup>2+</sup> with a molar ratio of 0–0.2. The substitution of DMA<sup>+</sup> can effectively passivate defects and inhibit non-radiative recombination. An appropriate amount of Mn<sup>2+</sup> doping optimizes the crystal structure, reduces the defects within the crystal, and increases the formation energy of the perovskite material. Under the optimal Mn<sup>2+</sup> content of <i>x</i> = 0.15, the doped MA<sub>0.5</sub>DMA<sub>0.5</sub>Pb<sub>0.85</sub>Mn<sub>0.15</sub>Br<sub>3</sub> PQDs exhibit high photoluminescence (PL) intensity, long fluorescence lifetime, and high storage and thermal stability. Finally, a white LED device is assembled by coating the MA<sub>0.5</sub>DMA<sub>0.5</sub>Pb<sub>0.85</sub>Mn<sub>0.15</sub>Br<sub>3</sub> PQDs and commercial red phosphor of (Sr, Ca)AlSiN<sub>3</sub>: Eu on a blue InGaN chip. The LED shows excellent color coordinates (0.373, 0.328), a color rendering index of 71, and a color temperature of 3808&#xa0;K. The A-site and B-site doping not only enhances the luminescence performance but also maintains good thermal stability, providing a technical pathway for improving the luminescence performance and reducing the toxicity of MAPbBr<sub>3</sub> PQDs. </p>

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Enhanced luminescence performance and stability of MAPbBr3 quantum dots by simultaneous substitution at A and B sites

  • 期刊论文

  • 发表日期：

    2025年8月7日

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  • Huidong Xie,
  • Siyu Zhang,
  • Xiaoling Guo,
  • Yunfan Bai,
  • Sijing Zhang,
  • Chang Yang

摘要

Organic–inorganic hybridized MAPbBr3 (CH3NH3+ = MA) perovskite quantum dots (PQDs) are promising photoelectronic materials for lighting and display applications. However, the toxicity of lead and their low stability greatly hinder their practical applications. A-site and B-site doping can increase fluorescence intensity, reduce Pb toxicity, and improve the stability. Herein, the effects of A-site and B-site doping on the crystal structure and optical properties of MAPbBr3 PQDs are investigated. First, the MAPbBr3 PQDs are A-site doped by dimethylammonium (DMA+) to methylammonium (MA+). Second, the Pb2+ ions in MA0.5DMA0.5PbBr3 PQDs are B-site doped by Mn2+ with a molar ratio of 0–0.2. The substitution of DMA+ can effectively passivate defects and inhibit non-radiative recombination. An appropriate amount of Mn2+ doping optimizes the crystal structure, reduces the defects within the crystal, and increases the formation energy of the perovskite material. Under the optimal Mn2+ content of x = 0.15, the doped MA0.5DMA0.5Pb0.85Mn0.15Br3 PQDs exhibit high photoluminescence (PL) intensity, long fluorescence lifetime, and high storage and thermal stability. Finally, a white LED device is assembled by coating the MA0.5DMA0.5Pb0.85Mn0.15Br3 PQDs and commercial red phosphor of (Sr, Ca)AlSiN3: Eu on a blue InGaN chip. The LED shows excellent color coordinates (0.373, 0.328), a color rendering index of 71, and a color temperature of 3808 K. The A-site and B-site doping not only enhances the luminescence performance but also maintains good thermal stability, providing a technical pathway for improving the luminescence performance and reducing the toxicity of MAPbBr3 PQDs.