Journal article
Charge trapping and coalescence dynamics in few layer MoS2
Publication Details
Authors: | Vega-Mayoral, V.; Borzda, T.; Vella, D.; Prijatelj, M.; Pogna, E.; Coleman, J.; Backes, C.; Cerullo, G.; Mihailovic, D.; Gadermaier, C. |
Publisher: | IOP PUBLISHING LTD |
Publication year: | 2018 |
Journal: | 2D Materials |
Pages range : | 015011 |
Volume number: | 5 |
Issue number: | 1 |
Number of pages: | 8 |
ISSN: | 2053-1583 |
DOI-Link der Erstveröffentlichung: |
Abstract
The optoelectronic properties of a material are determined by the processes following light-matter interaction. Here we use femtosecond optical spectroscopy to systematically study photoexcited carrier relaxation in few-layer MoS2 flakes as a function of excitation density and sample thickness. We find bimolecular coalescence of charges into indirect excitons as the dominant relaxation process in two-to three-layer flakes while thicker flakes show a much higher density of defects, which efficiently trap charges before they can coalesce.
The optoelectronic properties of a material are determined by the processes following light-matter interaction. Here we use femtosecond optical spectroscopy to systematically study photoexcited carrier relaxation in few-layer MoS2 flakes as a function of excitation density and sample thickness. We find bimolecular coalescence of charges into indirect excitons as the dominant relaxation process in two-to three-layer flakes while thicker flakes show a much higher density of defects, which efficiently trap charges before they can coalesce.
Keywords
femtosecond dynamics, liquid phase exfoliation, molybdenum disulfide, pump-probe, transition metal dichalcogenides, traps
