Bibliographic Details
| Title: |
Photoluminescence dynamics in few-layer InSe |
| Authors: |
Venanzi, Tommaso, Arora, Himani, Winnerl, Stephan, Pashkin, Alexej, Chava, Phanish, Patanè, Amalia, Kovalyuk, Zakhar D., Kudrynskyi, Zalhar R., Watanabe, Kenji, Taniguchi, Takashi, Erbe, Artur, Helm, Manfred, Schneider, Harald |
| Publication Year: |
2020 |
| Collection: |
Condensed Matter |
| Subject Terms: |
Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science |
| More Details: |
We study the optical properties of thin flakes of InSe encapsulated in hBN. More specifically, we investigate the photoluminescence (PL) emission and its dependence on sample thickness and temperature. Through the analysis of the PL lineshape, 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 bandgap electron-hole and defect-assisted recombination. The two recombination processes have lifetime of $\tau_1 \sim 8\;$ns and $\tau_2 \sim 100\;$ns, respectively. The relative weights of the direct bandgap and defect-assisted contributions show a strong layer dependence due to the direct-to-indirect bandgap 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 non-radiative recombinations.
Comment: The manuscript will be published in the journal Physical Review Materials. Copyright 2011 by American Physical Society (https://journals.aps.org/prmaterials/) |
| Document Type: |
Working Paper |
| Access URL: |
http://arxiv.org/abs/2003.12304 |
| Accession Number: |
edsarx.2003.12304 |
| Database: |
arXiv |
