Enhancing the Stability of CH3NH3PbBr3 Quantum Dots by Embedding in Silica Spheres Derived from Tetramethyl Orthosilicate in “Waterless” Toluene

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• 作者：Shouqiang Huang ; Zhichun Li ; Long Kong ; Nanwen Zhu ; Aidang Shan ; Liang Li
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：May 11, 2016
• 年：2016
• 卷：138
• 期：18
• 页码：5749-5752
• 全文大小：256K
• 年卷期：0
• ISSN：1520-5126

文摘

Methylammonium lead halide perovskites suffer from poor stability because of their high sensitivity to moisture. Inorganic material coatings of SiO₂ are preferred for coupling with perovskites to improve their stability, whereas the conventional SiO₂ formation method is unsuitable because it requires water. Here, a simple SiO₂ generation method based on the high hydrolysis rate of tetramethyl orthosilicate in analytical-grade toluene was developed to avoid the addition of water and catalyst. As a result, SiO₂-encapsulated CH₃NH₃PbBr₃ quantum dots (MAPB-QDs/SiO₂) were fabricated without decreasing the quantum yield. Photostability tests indicated that the MAPB-QDs/SiO₂ samples were markedly more stable than the unencapsulated MAPB-QDs. The photoluminescence (PL) of the MAPB-QDs/SiO₂ powders was maintained at 94.10% after 470 nm LED illumination for 7 h, which was much higher than the remnant PL (38.36%) of the pure MAPB-QD sample under a relative humidity of 60%. Similar test results were observed when the MAPB-QDs/SiO₂ powders were incorporated into the poly(methyl methacrylate) films. The enhanced photostability is ascribed to the SiO₂ barriers protecting the MAPB-QDs from degradation.