Bright magnetic dipole radiation from two-dimensional lead-halide perovskites
| Autor: | Naveen R. Venkatesan, Rashid Zia, Wenhao Li, Jon A. Schuller, Michael L. Chabinyc, Clayton J. Dahlman, Xinhong Du, Rhys M. Kennard, Ryan A. DeCrescent, Xie Zhang |
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| Rok vydání: | 2020 |
| Předmět: |
Magnetic dipole transition
Materials Science FOS: Physical sciences 02 engineering and technology 010402 general chemistry 01 natural sciences Radiation pattern Research Articles Physics Condensed Matter - Materials Science Multidisciplinary Condensed matter physics Sideband Scattering business.industry Materials Science (cond-mat.mtrl-sci) SciAdv r-articles 021001 nanoscience & nanotechnology cond-mat.mtrl-sci 3. Good health 0104 chemical sciences Dipole Semiconductor Light emission 0210 nano-technology business Magnetic dipole Research Article |
| Zdroj: | Science Advances Science advances, vol 6, iss 6 |
| ISSN: | 2375-2548 |
| DOI: | 10.1126/sciadv.aay4900 |
| Popis: | Light-matter interactions in semiconductor systems are uniformly treated within the electric dipole (ED) approximation, as multipolar interactions are considered "forbidden". Here, we demonstrate that this approximation inadequately describes light emission in novel two-dimensional hybrid organic-inorganic perovskite materials (2D HOIPs) --- a class of solution processable layered semiconductor with promising optoelectronic properties. Consequently, photoluminescence (PL) spectra become strongly dependent on the experimental geometry, a fact that is often overlooked, though critical for correct optical characterization of materials. Using energy-momentum and time-resolved spectroscopies, we experimentally demonstrate that low-energy sideband emission in 2D HOIPs exhibits a highly unusual, multipolar polarization and angle dependence. Using combined electromagnetic and quantum-mechanical analyses, we attribute this radiation pattern to an out-of-plane oriented magnetic dipole transition arising from the 2D character of the excited and ground state orbitals. Symmetry arguments point toward the presence of significant inversion symmetry-breaking mechanisms that are currently under great debate. These results provide a new perspective on the origins of unexpected sideband emission in HOIPs, clarify discrepancies in previous literature, and generally challenge the paradigm of ED-dominated light-matter interactions in novel optoelectronic materials. 8 Pages + References, 5 Figures, Supporting Information arXiv replace (2019/04/15): updated references, updated (optical power) units in Fig. 4, updated figure commentary, new supporting information figure |
| Databáze: | OpenAIRE |
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