Theory of edge-state optical absorption in two-dimensional transition metal dichalcogenide flakes


Type
Article
Change log
Authors
Trushin, M 
Kelleher, EJR 
Abstract

We develop an analytical model to describe sub-band-gap optical absorption in two-dimensional semiconducting transition metal dichalcogenide (s-TMD) nanoflakes. The material system represents an array of few-layer molybdenum disulfide crystals, randomly orientated in a polymer matrix. We propose that optical absorption involves direct transitions between electronic edge states and bulk bands, depends strongly on the carrier population, and is saturable with sufficient fluence. For excitation energies above half the band gap, the excess energy is absorbed by the edge-state electrons, elevating their effective temperature. Our analytical expressions for the linear and nonlinear absorption could prove useful tools in the design of practical photonic devices based on s-TMDs.

Description
Keywords
cond-mat.mes-hall, cond-mat.mes-hall, cond-mat.mtrl-sci
Journal Title
Physical Review B
Conference Name
Journal ISSN
2469-9950
2469-9969
Volume Title
94
Publisher
American Physical Society
Sponsorship
Royal Academy of Engineering, Collaborative Research Center 767