Intrinsic anion diffusivity in lead halide perovskites is facilitated by a soft lattice
| العنوان: | Intrinsic anion diffusivity in lead halide perovskites is facilitated by a soft lattice |
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| المؤلفون: | Lai, M, Obliger, A, Lu, D, Kley, CS, Bischak, CG, Kong, Q, Lei, T, Dou, L, Ginsberg, NS, Limmer, DT, Yang, P |
| المصدر: | Proceedings of the National Academy of Sciences of the United States of America, vol 115, iss 47 Lai, M; Obliger, A; Lu, D; Kley, CS; Bischak, CG; Kong, Q; et al.(2018). Intrinsic anion diffusivity in lead halide perovskites is facilitated by a soft lattice. Proceedings of the National Academy of Sciences of the United States of America, 115(47), 11929-11934. doi: 10.1073/pnas.1812718115. Lawrence Berkeley National Laboratory: Retrieved from: http://www.escholarship.org/uc/item/8771d2w7 |
| بيانات النشر: | eScholarship, University of California, 2018. |
| سنة النشر: | 2018 |
| مصطلحات موضوعية: | nanoscale imaging, MD Multidisciplinary, halide perovskite nanowire, anion diffusivity, soft lattice, molecular simulation |
| الوصف: | © 2018 National Academy of Sciences. All Rights Reserved. Facile ionic transport in lead halide perovskites plays a critical role in device performance. Understanding the microscopic origins of high ionic conductivities has been complicated by indirect measurements and sample microstructural heterogeneities. Here, we report the direct visualization of halide anion interdiffusion in CsPbCl3–CsPbBr3 single crystalline perovskite nanowire heterojunctions using wide-field and confocal photoluminescence measurements. The combination of nanoscale imaging techniques with these single crystalline materials allows us to measure intrinsic anionic lattice diffusivities, free from complications of micro-scale inhomogeneity. Halide diffusivities were found to be between 10−13 and ∼10−12 cm2/second at about 100 °C, which are several orders of magnitudes lower than those reported in polycrystalline thin films. Spatially resolved photoluminescence lifetimes and surface potential measurements provide evidence of the central role of halide vacancies in facilitating ionic diffusion. Vacancy formation free energies computed from molecular simulation are small due to the easily deformable perovskite lattice, accounting for the high equilibrium vacancy concentration. Furthermore, molecular simulations suggest that ionic motion is facilitated by low-frequency lattice modes, resulting in low activation barriers for vacancy-mediated transport. This work elucidates the intrinsic solid-state ion diffusion mechanisms in this class of semisoft materials and offers guidelines for engineering materials with long-term stability in functional devices. |
| وصف الملف: | application/pdf |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=dedup_wf_001::82a2e7c42b7d0c78bc65ee150b932875 https://escholarship.org/uc/item/8771d2w7 |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.dedup.wf.001..82a2e7c42b7d0c78bc65ee150b932875 |
| قاعدة البيانات: | OpenAIRE |
| الوصف غير متاح. |