Charge trapping and coalescence dynamics in few layer MoS2. (16th October 2017)

• Record Type: Journal Article
• Authors: Vega-Mayoral, Victor; Borzda, Tetiana; Vella, Daniele; Prijatelj, Matej; Pogna, Eva A A; Backes, Claudia; Coleman, Jonathan N; Cerullo, Giulio; Mihailovic, Dragan; Gadermaier, Christoph
• Is Part Of: 2D materials. Volume 5:Number 1(2018)
• Publication Date: 2017-10-16
• Subjects: molybdenum disulfide -- transition metal dichalcogenides -- liquid phase exfoliation -- pump–probe -- femtosecond dynamics -- traps -- defects; Graphene -- Periodicals; Materials science -- Periodicals; Nanostructured materials -- Periodicals; 620.115
• DOI: 10.1088/2053-1583/aa8d42
• Languages: English
• ISSNs: 2053-1583

Abstract

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.