Supertransport of excitons in atomically thin organic semiconductors at the 2D quantum limit.

Autor:	Sharma A; Research School of Electrical, Energy and Materials Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601 Australia., Zhang L; Research School of Electrical, Energy and Materials Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601 Australia., Tollerud JO; Optical Sciences Centre, Swinburne University of Technology, Hawthorn, VIC 3122 Australia.; ARC Centre of Excellence for Future Low-Energy Electronics Technology, Australia., Dong M; Research School of Electrical, Energy and Materials Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601 Australia., Zhu Y; Research School of Electrical, Energy and Materials Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601 Australia., Halbich R; Research School of Electrical, Energy and Materials Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601 Australia., Vogl T; Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University, Acton, ACT 2601 Australia., Liang K; Research School of Electrical, Energy and Materials Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601 Australia.; School of Mechatronical Engineering, Beijing Institute of Technology, Beijing, 100081 China., Nguyen HT; Research School of Electrical, Energy and Materials Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601 Australia., Wang F; Institute for Biomedical Materials and Devices (IBMD), Faculty of Science, University of Technology Sydney, Sydney, NSW 2007 Australia., Sanwlani S; Optical Sciences Centre, Swinburne University of Technology, Hawthorn, VIC 3122 Australia.; ARC Centre of Excellence for Future Low-Energy Electronics Technology, Australia., Earl SK; Optical Sciences Centre, Swinburne University of Technology, Hawthorn, VIC 3122 Australia.; ARC Centre of Excellence for Future Low-Energy Electronics Technology, Australia., Macdonald D; Research School of Electrical, Energy and Materials Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601 Australia., Lam PK; Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University, Acton, ACT 2601 Australia., Davis JA; Optical Sciences Centre, Swinburne University of Technology, Hawthorn, VIC 3122 Australia.; ARC Centre of Excellence for Future Low-Energy Electronics Technology, Australia., Lu Y; Research School of Electrical, Energy and Materials Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601 Australia.; ARC Centre of Excellence for Future Low-Energy Electronics Technology, Australia.; Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University, Acton, ACT 2601 Australia.
Jazyk:	angličtina
Zdroj:	Light, science & applications [Light Sci Appl] 2020 Jul 06; Vol. 9, pp. 116. Date of Electronic Publication: 2020 Jul 06 (Print Publication: 2020).
DOI:	10.1038/s41377-020-00347-y
Abstrakt:	Long-range and fast transport of coherent excitons is important for the development of high-speed excitonic circuits and quantum computing applications. However, most of these coherent excitons have only been observed in some low-dimensional semiconductors when coupled with cavities, as there are large inhomogeneous broadening and dephasing effects on the transport of excitons in their native states in materials. Here, by confining coherent excitons at the 2D quantum limit, we first observed molecular aggregation-enabled 'supertransport' of excitons in atomically thin two-dimensional (2D) organic semiconductors between coherent states, with a measured high effective exciton diffusion coefficient of ~346.9 cm 2 /s at room temperature. This value is one to several orders of magnitude higher than the values reported for other organic molecular aggregates and low-dimensional inorganic materials. Without coupling to any optical cavities, the monolayer pentacene sample, a very clean 2D quantum system (~1.2 nm thick) with high crystallinity (J-type aggregation) and minimal interfacial states, showed superradiant emission from Frenkel excitons, which was experimentally confirmed by the temperature-dependent photoluminescence (PL) emission, highly enhanced radiative decay rate, significantly narrowed PL peak width and strongly directional in-plane emission. The coherence in monolayer pentacene samples was observed to be delocalised over ~135 molecules, which is significantly larger than the values (a few molecules) observed for other organic thin films. In addition, the supertransport of excitons in monolayer pentacene samples showed highly anisotropic behaviour. Our results pave the way for the development of future high-speed excitonic circuits, fast OLEDs, and other optoelectronic devices. Competing Interests: Conflict of interestThe authors declare that they have no conflict of interest. (© The Author(s) 2020.)
Databáze:	MEDLINE
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