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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Evolution of Raman Scattering and Electronic Structure of Ultrathin Molybdenum Disulfide by Oxygen Chemisorption
TL;DR: In this paper, a new method to introduce oxygen chemisorption in ultrathin MoS2 by controlled oxygen plasma treatment is presented, using Raman spectroscopy, a red shift in the frequency of E12g mode with increasing oxygen chemi cation is found, whereas, the frequency for A1g mode is fixed.
Journal ArticleDOI
Heteroatoms/molecules to tune the properties of 2D materials
TL;DR: In this article, three main kinds of strategies (doping, intercalation and surface modification) are displayed and corresponding examples for each detailed branch are listed to discuss the advantages and disadvantages.
Journal ArticleDOI
Spatial non-uniformity in exfoliated WS2 single layers
Ioannis Paradisanos,Ioannis Paradisanos,N. Pliatsikas,Panos Patsalas,Costas Fotakis,Costas Fotakis,Emmanuel Kymakis,Emmanuel Kymakis,George Kioseoglou,George Kioseoglou,Emmanuel Stratakis,Emmanuel Stratakis +11 more
TL;DR: The results shed light on the role of the chemical bonding in the competition between exciton complexes in monolayer WS2, providing a method of engineering new nanophotonic functions using WS2 monolayers.
Journal ArticleDOI
Response of MoS2 nanosheet field effect transistor under different gas environments and its long wavelength photoresponse characteristics
TL;DR: In this article, the electrical properties of MoS 2 nanosheet field effect transistor (NSFET) under air and NH 3 environments are studied both by experiment measurements and theoretical calculations, and the experimental results illustrate that the performance of NSFET is distinctly altered under NH 3 environment.
Journal ArticleDOI
CVD grown 2D MoS2 layers: A photoluminescence and fluorescence lifetime imaging study
Ayberk Özden,Huseyin Sar,Aydan Yeltik,Büşra Madenoğlu,Cem Sevik,Feridun Ay,Nihan Kosku Perkgoz +6 more
TL;DR: In this paper, the fluorescence lifetime imaging and accompanying photoluminescence properties of a chemical vapour deposition (CVD) grown atomically thin material, MoS2, were investigated.
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