Symmetrization of the Crystal Lattice of MAPbI3 Boosts the Performance and Stability of Metal-Perovskite Photodiodes
Symmetrization of the Crystal Lattice of MAPbI3 Boosts the Performance and Stability of Metal-Perovskite Photodiodes
复制标题
MAPbI(3)晶格的对称化提高了金属钙钛矿光电二极管的性能和稳定性
DOI：
10.1002/adma.201701656
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发表时间：
2017-08-11
影响因子：
29.4
通讯作者：
Mi, Qixi
中科院分区：
文献类型：
--
作者：
Shi, Zhifang;Zhang, Yi;Mi, Qixi
半导体三碘化铅钙钛矿（APbI（3））在光致发光和电致发光等应用中表现出优异的性能。尽管APbI（3）中A（+）存在许多理论上的可能性，但目前的实验知识主要限于其中两种材料：甲基铵（MA（+））和甲脒（FA（+））三碘化铅，这两种材料在室温下都没有采用理想的立方钙钛矿结构。在此，提出了立方APbI（3）稳定的基于体积的判据，并引入了两种钙钛矿材料MA（1-x）EA（x）PbI（3）（MEPI，EA（+）=乙基铵）和MA（1-y）DMA（y）PbI（3）（MDPI，DMA（+）=二甲基铵）。X射线粉末衍射和单晶衍射结果表明，MEPI和MDPI均为立方钙钛矿结构的固溶体，EA（+）和DMA（+）阳离子在MAPbI（3）的晶格对称化中起着相似的作用。MEPI和MDPI的单晶生长并制成一系列厚度的板，然后制成金属钙钛矿光电二极管。相对于当前的基准MAPbI（3），这些器件表现出三倍的扩散长度和大约十倍的防潮稳定性增强。在这项研究中，材料设计和器件制造的系统方法大大扩展了钙钛矿半导体的候选池，并为高性能单晶钙钛矿器件（包括太阳能电池和发光体）铺平了道路。
Semiconducting lead triiodide perovskites (APbI(3)) have shown remarkable performance in applications including photovoltaics and electroluminescence. Despite many theoretical possibilities for A(+) in APbI(3), the current experimental knowledge is largely limited to two of these materials: methylammonium (MA(+)) and formamidinium (FA(+)) lead triiodides, neither of which adopts the ideal, cubic perovskite structure at room temperature. Here, a volume-based criterion is proposed for cubic APbI(3) to be stable, and two perovskite materials MA(1-x)EA(x)PbI(3) (MEPI, EA(+) = ethylammonium) and MA(1-y)DMA(y)PbI(3) (MDPI, DMA(+) = dimethylammonium) are introduced. Powder and single-crystal X-ray diffraction (XRD) results reveal that MEPI and MDPI are solid solutions possessing the cubic perovskite structure, and the EA(+) and DMA(+) cations play similar roles in the symmetrization of the crystal lattice of MAPbI(3). Single crystals of MEPI and MDPI are grown and made into plates of a range of thicknesses, and then into metal-perovskite photodiodes. These devices exhibit tripled diffusion lengths and about tenfold enhancement in stability against moisture, both relative to the current benchmark MAPbI(3). In this study, the systematic approach to materials design and device fabrication greatly expands the candidate pool of perovskite semiconductors, and paves the way for high-performance, single-crystal perovskite devices including solar cells and light emitters.