Strong optical response and light emission from a monolayer molecular crystal



Zhao, Huijuan, Zhao, Yingbo, Song, Yinxuan, Zhou, Ming, Lv, Wei, Tao, Liu, Feng, Yuzhang, Song, Biying, Ma, Yue, Zhang, Junqing
et al (show 16 more authors) (2019) Strong optical response and light emission from a monolayer molecular crystal. NATURE COMMUNICATIONS, 10 (1). 5589-.

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Abstract

Excitons in two-dimensional (2D) materials are tightly bound and exhibit rich physics. So far, the optical excitations in 2D semiconductors are dominated by Wannier-Mott excitons, but molecular systems can host Frenkel excitons (FE) with unique properties. Here, we report a strong optical response in a class of monolayer molecular J-aggregates. The exciton exhibits giant oscillator strength and absorption (over 30% for monolayer) at resonance, as well as photoluminescence quantum yield in the range of 60-100%. We observe evidence of superradiance (including increased oscillator strength, bathochromic shift, reduced linewidth and lifetime) at room-temperature and more progressively towards low temperature. These unique properties only exist in monolayer owing to the large unscreened dipole interactions and suppression of charge-transfer processes. Finally, we demonstrate light-emitting devices with the monolayer J-aggregate. The intrinsic device speed could be beyond 30 GHz, which is promising for next-generation ultrafast on-chip optical communications.

Item Type: Article
Uncontrolled Keywords: 5108 Quantum Physics, 40 Engineering, 51 Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 18 Feb 2020 11:51
Last Modified: 21 Jun 2024 08:27
DOI: 10.1038/s41467-019-13581-9
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3075402