Hintermayr Verena A, Lampe Carola, Löw Maximilian, Roemer Janina, Vanderlinden Willem, Gramlich Moritz, Böhm Anton X, Sattler Cornelia, Nickel Bert, Lohmüller Theobald, Urban Alexander S
Chair for Photonics and Optoelectronics, Nano-Institute Munich, Department of Physics , Ludwig-Maximilians-Universität München , Königinstrasse 10 , 80539 Munich , Germany.
Nanosystems Initiative Munich (NIM) and Center for NanoScience (CeNS) , Schellingstrasse 4 , 80799 Munich , Germany.
Nano Lett. 2019 Aug 14;19(8):4928-4933. doi: 10.1021/acs.nanolett.9b00982. Epub 2019 Jul 30.
Halide perovskite nanocrystals (NCs) have shown impressive advances, exhibiting optical properties that outpace conventional semiconductor NCs, such as near-unity quantum yields and ultrafast radiative decay rates. Nevertheless, the NCs suffer even more from stability problems at ambient conditions and due to moisture than their bulk counterparts. Herein, we report a strategy of employing polymer micelles as nanoreactors for the synthesis of methylammonium lead trihalide perovskite NCs. Encapsulated by this polymer shell, the NCs display strong stability against water degradation and halide ion migration. Thin films comprising these NCs exhibit a more than 15-fold increase in lifespan in comparison to unprotected NCs in ambient conditions and even survive over 75 days of complete immersion in water. Furthermore, the NCs, which exhibit quantum yields of up to 63% and tunability of the emission wavelength throughout the visible range, show no signs of halide ion exchange. Additionally, heterostructures of MAPI and MAPBr NC layers exhibit efficient Förster resonance energy transfer (FRET), revealing a strategy for optoelectronic integration.
卤化物钙钛矿纳米晶体（NCs）已取得了令人瞩目的进展，展现出超越传统半导体纳米晶体的光学特性，如近乎单位的量子产率和超快的辐射衰减率。然而，与体相材料相比，这些纳米晶体在环境条件下以及受潮时更易出现稳定性问题。在此，我们报道了一种利用聚合物胶束作为纳米反应器来合成甲基铵三卤化铅钙钛矿纳米晶体的策略。被这种聚合物壳层包裹后，纳米晶体对水降解和卤离子迁移表现出很强的稳定性。与在环境条件下未受保护的纳米晶体相比，包含这些纳米晶体的薄膜寿命增加了15倍以上，甚至在完全浸入水中75天以上仍能存活。此外，量子产率高达63%且发射波长在整个可见光范围内具有可调性的纳米晶体，未显示出卤离子交换的迹象。此外，MAPI和MAPBr纳米晶体层的异质结构表现出高效的Förster共振能量转移（FRET），揭示了一种光电集成策略。
