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DOI | 10.1038/nature25493 |
Bright triplet excitons in caesium lead halide perovskites | |
Becker, Michael A.1,2; Vaxenburg, Roman3; Nedelcu, Georgian4,5; Sercel, Peter C.6; Shabaev, Andrew3; Mehl, Michael J.7; Michopoulos, John G.8; Lambrakos, Samuel G.8; Bernstein, Noam8; Lyons, John L.8; Stoferle, Thilo1; Mahrt, Rainer F.1; Kovalenko, Maksym V.4,5; Norris, David J.2; Raino, Gabriele1,4; Efros, Alexander L.8 | |
2018-01-11 | |
发表期刊 | NATURE |
ISSN | 0028-0836 |
EISSN | 1476-4687 |
出版年 | 2018 |
卷号 | 553期号:7687页码:189-+ |
文章类型 | Article |
语种 | 英语 |
国家 | Switzerland; USA |
英文摘要 | Nanostructured semiconductors emit light from electronic states known as excitons(1). For organic materials, Hund's rules(2) state that the lowest-energy exciton is a poorly emitting triplet state. For inorganic semiconductors, similar rules(3) predict an analogue of this triplet state known as the 'dark exciton'(4). Because dark excitons release photons slowly, hindering emission from inorganic nanostructures, materials that disobey these rules have been sought. However, despite considerable experimental and theoretical efforts, no inorganic semiconductors have been identified in which the lowest exciton is bright. Here we show that the lowest exciton in caesium lead halide perovskites (CsPbX3, with X = Cl, Br or I) involves a highly emissive triplet state. We first use an effective-mass model and group theory to demonstrate the possibility of such a state existing, which can occur when the strong spin-orbit coupling in the conduction band of a perovskite is combined with the Rashba effect(5-10). We then apply our model to CsPbX3 nanocrystals(11), and measure size-and composition-dependent fluorescence at the single-nanocrystal level. The bright triplet character of the lowest exciton explains the anomalous photon-emission rates of these materials, which emit about 20 and 1,000 times faster(12) than any other semiconductor nanocrystal at room(13-16) and cryogenic(4) temperatures, respectively. The existence of this bright triplet exciton is further confirmed by analysis of the fine structure in low-temperature fluorescence spectra. For semiconductor nanocrystals, which are already used in lighting(17), lasers(18) and displays(19), these excitons could lead to materials with brighter emission. More generally, our results provide criteria for identifying other semiconductors that exhibit bright excitons, with potential implications for optoelectronic devices. |
领域 | 地球科学 ; 气候变化 ; 资源环境 |
收录类别 | SCI-E |
WOS记录号 | WOS:000419794800033 |
WOS关键词 | INITIO MOLECULAR-DYNAMICS ; DARK-EXCITON ; QUANTUM ; RASHBA ; NANOCRYSTALS ; EMISSION ; LUMINESCENCE ; TRANSITION ; BLINKING ; LIFETIME |
WOS类目 | Multidisciplinary Sciences |
WOS研究方向 | Science & Technology - Other Topics |
URL | 查看原文 |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/202853 |
专题 | 地球科学 资源环境科学 气候变化 |
作者单位 | 1.IBM Res Zurich, Saumerstr 4, CH-8803 Ruschlikon, Switzerland; 2.Swiss Fed Inst Technol, Dept Mech & Proc Engn, Opt Mat Engn Lab, CH-8092 Zurich, Switzerland; 3.George Mason Univ, Computat Mat Sci Ctr, Fairfax, VA 22030 USA; 4.Swiss Fed Inst Technol, Dept Chem & Appl Biosci, Inst Inorgan Chem, CH-8093 Zurich, Switzerland; 5.Empa, Swiss Fed Labs Mat Sci & Technol, Lab Thin Films & Photovolta, CH-8600 Dubendorf, Switzerland; 6.CALTECH, TJ Watson Lab Appl Phys, Pasadena, CA 91125 USA; 7.US Naval Acad, Annapolis, MD 21402 USA; 8.Naval Res Lab, Ctr Computat Mat Sci, Washington, DC 20375 USA |
推荐引用方式 GB/T 7714 | Becker, Michael A.,Vaxenburg, Roman,Nedelcu, Georgian,et al. Bright triplet excitons in caesium lead halide perovskites[J]. NATURE,2018,553(7687):189-+. |
APA | Becker, Michael A..,Vaxenburg, Roman.,Nedelcu, Georgian.,Sercel, Peter C..,Shabaev, Andrew.,...&Efros, Alexander L..(2018).Bright triplet excitons in caesium lead halide perovskites.NATURE,553(7687),189-+. |
MLA | Becker, Michael A.,et al."Bright triplet excitons in caesium lead halide perovskites".NATURE 553.7687(2018):189-+. |
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