Light emission from the layered metal 2H-TaSe2 and its potential applications
Abstract
Conventional metals, in general, do not exhibit strong photoluminescence. 2H-TaSe2 is a layered transition metal dichalcogenide that possesses metallic property with charge density wave characteristics. Here we show that 2H-TaSe2 exhibits a surprisingly strong optical absorption and photoluminescence resulting from inter-band transitions. We use this perfect combination of electrical and optical properties in several optoelectronic applications. We show a sevenfold enhancement in the photoluminescence intensity of otherwise weakly luminescent multi-layer MoS2 through non-radiative resonant energy transfer from TaSe2 transition dipoles. Using a combination of scanning photocurrent and time-resolved photoluminescence measurements, we also show that the hot electrons generated by light absorption in TaSe2 have a rather long lifetime unlike conventional metals, making TaSe2 an excellent hot electron injector. Finally, we show a vertical TaSe2/MoS2/graphene photodetector demonstrating a responsivity of >10 AW-1 at 0.1 MHz—one of the fastest reported photodetectors using MoS2.
- Publication:
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Communications Physics
- Pub Date:
- July 2019
- DOI:
- 10.1038/s42005-019-0190-0
- arXiv:
- arXiv:1908.06913
- Bibcode:
- 2019CmPhy...2...88M
- Keywords:
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- Condensed Matter - Mesoscale and Nanoscale Physics;
- Condensed Matter - Materials Science
- E-Print:
- Communications Physics, Volume 2, Article number 88, 2019