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1 PublicationPhotoluminescence dynamics in few-layer InSe
Venanzi, T.; Arora, H.; Winnerl, S.; Pashkin, O.; Chava, P.; Patanè, A.; Kovalyuk, Z. D.; Kudrynskyi, Z. R.; Watanabe, K.; Taniguchi, T.; Erbe, A.; Helm, M.; Schneider, H.
We study the optical properties of thin flakes of InSe encapsulated in hexagonal boron nitride. More specifically, we investigate the photoluminescence (PL) emission and its dependence on sample thickness and temperature. Through the analysis of the PL line shape, we discuss the relative weights of the exciton and electron-hole contributions. Thereafter we investigate the PL dynamics. Two contributions are distinguishable at low temperature: direct band-gap electron-hole and defect-assisted recombination. The two recombination processes have lifetimes ofτ1∼8ns andτ2∼100 ns, respectively. The relative weights of the direct band-gap and defect-assisted contributions show a strong layer dependence due to the direct-to-indirect band-gap crossover. Electron-hole PL lifetime is limited by population transfer to lower-energy states and no dependence on the number of layers was observed. The lifetime of the defect-assisted recombination gets longer for thinner samples. Finally, we show that the PL lifetime decreases at high temperatures as a consequence of more efficient nonradiative recombinations.
Keywords: 2D semiconductors; time-resolved photoluminescence
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Data for: Photoluminescence dynamics in few-layer InSe
ROBIS: 30918 HZDR-primary research data are used by this (Id 30917) publication
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Physical Review Materials 4(2020)4, 044001
DOI: 10.1103/PhysRevMaterials.4.044001
Cited 16 times in Scopus
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Permalink: https://www.hzdr.de/publications/Publ-30917