Journal ArticleDOI
Broad-range modulation of light emission in two-dimensional semiconductors by molecular physisorption gating.
Sefaattin Tongay,Jian Zhou,Can Ataca,Jonathan Liu,Jeong Seuk Kang,Tyler S. Matthews,Long You,Jingbo Li,Jeffrey C. Grossman,Junqiao Wu,Junqiao Wu +10 more
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TLDR
Physi-sorbed O2 and/or H2O molecules electronically deplete n-type materials such as MoS2 and MoSe2, which weakens electrostatic screening that would otherwise destabilize excitons, leading to the drastic enhancement in photoluminescence.Abstract:
In the monolayer limit, transition metal dichalcogenides become direct-bandgap, light-emitting semiconductors. The quantum yield of light emission is low and extremely sensitive to the substrate used, while the underlying physics remains elusive. In this work, we report over 100 times modulation of light emission efficiency of these two-dimensional semiconductors by physical adsorption of O2 and/or H2O molecules, while inert gases do not cause such effect. The O2 and/or H2O pressure acts quantitatively as an instantaneously reversible “molecular gating” force, providing orders of magnitude broader control of carrier density and light emission than conventional electric field gating. Physi-sorbed O2 and/or H2O molecules electronically deplete n-type materials such as MoS2 and MoSe2, which weakens electrostatic screening that would otherwise destabilize excitons, leading to the drastic enhancement in photoluminescence. In p-type materials such as WSe2, the molecular physisorption results in the opposite eff...read more
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Tailoring the phase transition and electron-phonon coupling in 1 T ' -Mo Te 2 by charge doping: A Raman study
TL;DR: In this paper, the phase transition in transition metal dichalcogenides has been studied as a function of flake thickness and charge doping, and it has been shown that the transition metal transition metal can be stabilised by charge doping.
Journal ArticleDOI
Activating MoS2 basal planes for hydrogen evolution through direct CVD morphology control
TL;DR: In this paper, a hexagonal MoS2 was synthesized with high surface coverage and abundant highly distributed S vacancies as active reaction sites directly by chemical vapor deposition (CVD)-grown monolayers.
Journal ArticleDOI
Photoactivation of Strong Photoluminescence in Superacid-Treated Monolayer Molybdenum Disulfide.
Yuki Yamada,Keisuke Shinokita,Yasuo Okajima,Sakura N. Takeda,Yuji Matsushita,Kuniharu Takei,Takeshi Yoshimura,Atsushi Ashida,Norifumi Fujimura,Kazunari Matsuda,Daisuke Kiriya,Daisuke Kiriya +11 more
TL;DR: Light is shed on environmental factors to activate the photoluminescence intensity of the TFSI-treated monolayer MoS2, with a factor of more than two orders of magnitude greater than the original by photoactivation, which can serve as a basis for engineering the bright atomically thin materials for 2D optoelectronics.
Journal ArticleDOI
Photoluminescence nonuniformity from self-seeding nuclei in CVD-grown monolayer MoSe2.
TL;DR: The observed behaviors of a large shift in the photoluminescence peak position at the edge and biexciton emissions in the inner region confirm that the monolayer MoSe2 crystals grow from nucleation centers during the CVD process.
Journal ArticleDOI
Effect of Cu concentration and dopant site on the band gap of MoS2: A DFT study
Akhtar Hussain,Muhammad Tayyab +1 more
TL;DR: In this paper, the structural and electronic properties of molybdenum disulfide (MoS2) by doping a varying concentration of Cu as impurity were investigated using density functional theory.
References
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Journal ArticleDOI
Generalized Gradient Approximation Made Simple
TL;DR: A simple derivation of a simple GGA is presented, in which all parameters (other than those in LSD) are fundamental constants, and only general features of the detailed construction underlying the Perdew-Wang 1991 (PW91) GGA are invoked.
Journal ArticleDOI
Projector augmented-wave method
TL;DR: An approach for electronic structure calculations is described that generalizes both the pseudopotential method and the linear augmented-plane-wave (LAPW) method in a natural way and can be used to treat first-row and transition-metal elements with affordable effort and provides access to the full wave function.
Journal ArticleDOI
Ab initio molecular dynamics for liquid metals.
Georg Kresse,Jürgen Hafner +1 more
TL;DR: In this paper, the authors present an ab initio quantum-mechanical molecular-dynamics calculations based on the calculation of the electronic ground state and of the Hellmann-Feynman forces in the local density approximation.
Journal ArticleDOI
Semiempirical GGA-type density functional constructed with a long-range dispersion correction.
TL;DR: A new density functional of the generalized gradient approximation (GGA) type for general chemistry applications termed B97‐D is proposed, based on Becke's power‐series ansatz from 1997, and is explicitly parameterized by including damped atom‐pairwise dispersion corrections of the form C6 · R−6.
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Atomically thin MoS2: a new direct-gap semiconductor
TL;DR: The electronic properties of ultrathin crystals of molybdenum disulfide consisting of N=1,2,…,6 S-Mo-S monolayers have been investigated by optical spectroscopy and the effect of quantum confinement on the material's electronic structure is traced.