Theory of edge-state optical absorption in two-dimensional transition metal dichalcogenide flakes
arXiv:1602.06298 · doi:10.1103/PhysRevB.94.155301
Abstract
We develop an analytical model to describe sub-bandgap 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 bandgap, 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.
10 pages, 4 figures, typos fixed as published
References in corpus (10)
- Electronic States of Graphene Nanoribbons
- k.p theory for two-dimensional transition metal dichalcogenide semiconductors
- Wideband saturable absorption in few-layer molybdenum diselenide (MoSe2) for Q-switching Yb-, Er- and Tm-doped fiber lasers
- Surface Recombination Limited Lifetimes of Photoexcited Carriers in Few-Layer Transition Metal Dichalcogenide MoS2
- Stability of boron nitride bilayers: Ground state energies, interlayer distances, and tight-binding description
- Ultrafast pseudospin dynamics in graphene
- Edge states in graphene-like systems
- Edge states in dichalcogenide nanoribbons and triangular quantum dots
- Boundary conditions for transition-metal dichalcogenide monolayers in the continuum model
- Experimental determination of the massive Dirac fermion model parameters for MoS, MoSe, WS, and WSe