相关论文: Quasiparticle Band Gaps, Excitonic Effects, and An…
The layer dependent structural, electronic and vibrational properties of SnS2 and SnSe2 are investigated using first-principles density functional theory (DFT). The in-plane lattice constants, interlayer distances and binding energies are…
Atomic scale defects in semiconductors enable their technological applications and realization of novel quantum states. Using scanning tunneling microscopy and spectroscopy complemented by ab-initio calculations we determine the nature of…
Exciton dissociation plays a crucial role in the performance of optoelectronic devices based on two-dimensional (2D) transition metal dichalcogenides (TMDs). In this work, we investigate the effect of an in-plane electric field on the…
We characterize the electronic structure and elasticity of monolayer transition-metal dichalcogenides MX2 (M=Mo, W, Sn, Hf and X=S, Se, Te) with 2H and 1T structures using fully relativistic first principles calculations based on density…
Controlled variation of the electronic properties of 2D materials by applying strain has emerged as a promising way to design materials for customized applications. Using first principles density functional theory calculations, we show that…
Optoelectronic excitations in monolayer MoS2 manifest from a hierarchy of electrically tunable, Coulombic free-carrier and excitonic many-body phenomena. Investigating the fundamental interactions underpinning these phenomena - critical to…
In quasi-1D $\pi$-conjugated polymers such as \emph{trans}-polyacetylene and polyenes, electron correlation effects determine the "reversed" excited state ordering in which the lowest two-photon $2A_{g}$ state lies below the lowest…
Two-dimensional (2D) transition metal dichalcogenide (TMD) materials have versatile electronic and optical properties. TMD nanoribbons show interesting properties due to reduced dimensionality, quantum confinement, and edge states. Tang et…
Misfit compounds are thermodynamically stable stacks of two-dimensional materials, forming a three-dimensional structure that remains incommensurate in one direction parallel to the layers. As a consequence, no true bonding is expected…
Atomic-scale control of light-matter interactions represent the ultimate frontier for many applications in photonics and quantum technology. Two-dimensional semiconductors, including transition metal dichalcogenides, are a promising…
The millimeter sized monolayer and bilayer 2H-MoTe2 single crystal samples are prepared by a new mechanical exfoliation method. Based on such high-quality samples, we report the first direct electronic structure study on them, using…
Due to the absence of interlayer coupling and inversion symmetry, transition metal dichalcogenide (MX$_2$) semiconductor monolayers exhibit novel properties that are distinctly different from their bulk crystals such as direct optical band…
We present low temperature magneto-photoluminescence experiments which demonstrate the brightening of dark excitons by an in-plane magnetic field $B$ applied to monolayers of different semiconducting transition metal dichalcogenides. For…
The electronic and optical properties of transition metal dichalcogenides (TMDCs) in distinctive phases, such as 1H, 1T, and 1T' phases, are of fundamental importance for variety of applications. The 1H phase has been understood as a direct…
Modulation of electronic properties of materials by electric fields is central to the operation of modern semiconductor devices, providing access to complex electronic behaviors and greater freedom in tuning the energy bands of materials.…
Applying elastic deformation can tune a material physical properties locally and reversibly. Spatially modulated lattice deformation can create a bandgap gradient, favouring photo-generated charge separation and collection in optoelectronic…
A WSe2 monolayer of 1T' phase is a large band gap quantum spin Hall insulator, supporting dissipationless charge and spin transports through the topologically protected edge states. In this work, we explore the nanoribbon forms of 1T' phase…
Strong Coulomb correlations together with multi-valley electronic bands in the presence of spin-orbit interaction and possible new optoelectronic applications are at the heart of studies of the rich physics of excitons in semiconductor…
Monolayers (MLs) of MoS2 and WSe2 are 2D semiconductors with strong, direct optical transitions that are governed by tightly Coulomb bound eletron-hole pairs (excitons). The optoelectronic properties of these transition metal…
Monolayer two-dimensional transitional metal dichalcogenides, such as MoS2, WS2 and WSe2, are direct band gap semiconductors with large exciton binding energy. They attract growing attentions for opto-electronic applications including solar…