Poellmann, C. and Steinleitner, P. and Leierseder, U. and Nagler, P. and Plechinger, G. and Porer, M. and Bratschitsch, R. and Schueller, C. and Korn, T. and Huber, R. (2015) Resonant internal quantum transitions and femtosecond radiative decay of excitons in monolayer WSe2. NATURE MATERIALS, 14 (9). 889-+. ISSN 1476-1122, 1476-4660
Full text not available from this repository. (Request a copy)Abstract
Atomically thin two-dimensional crystals have revolutionized materials science(1-3). In particular, monolayer transition metal dichalcogenides promise novel optoelectronic applications, owing to their direct energy gaps in the optical range(4-9). Their electronic and optical properties are dominated by Coulomb-bound electron-hole pairs called excitons(10-18), whose unusual internal structure(13), symmetry(15-17), many-body effects(18) and dynamics have been vividly discussed. Here we report the first direct experimental access to all 1s A excitons, regardless of momentum-inside and outside the radiative cone-in single-layerWSe(2). Phase-locked mid-infrared pulses reveal the internal orbital 1s-2p resonance, which is highly sensitive to the shape of the excitonic envelope functions and provides accurate transition energies, oscillator strengths, densities and linewidths. Remarkably, the observed decay dynamics indicates an ultrafast radiative annihilation of small-momentum excitons within 150 fs, whereas Auger recombination prevails for optically dark states. The results provide a comprehensive view of excitons and introduce a new degree of freedom for quantum control, optoelectronics and valleytronics of dichalcogenide monolayers(19-24).
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | 2-DIMENSIONAL MATERIALS; VALLEY POLARIZATION; GENERATION; MOS2; PHOTOLUMINESCENCE; |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Experimental and Applied Physics > Chair Professor Huber > Group Rupert Huber Physics > Institute of Experimental and Applied Physics > Chair Professor Lupton > Group Christian Schüller |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 13 Jun 2019 14:03 |
| Last Modified: | 13 Jun 2019 14:03 |
| URI: | https://pred.uni-regensburg.de/id/eprint/4948 |
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