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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Ultrafast charge dynamics in dispersions of monolayer MoS2 nanosheets
TL;DR: In this article, the ultrafast charge dynamics in dispersions of MoS2 nanosheets in N-methyl-2-pyrrolidone were studied via transient absorption spectroscopy, and the growth and decay of the features in the B exciton region were determined largely by the dynamics of the exciton population.
Journal ArticleDOI
Grain-Boundary Engineering of Monolayer MoS2 for Energy-Efficient Lateral Synaptic Devices.
Xuewen Wang,Bolun Wang,Qinghua Zhang,Yufei Sun,Enze Wang,Hao Luo,Yonghuang Wu,Lin Gu,Huanglong Li,Kai Liu +9 more
TL;DR: In this article, four-terminal, lateral synaptic devices with artificially engineered grain boundaries (GBs) are reported, which are made from monolayer MoS2 and have shortterm and long-term plasticity characteristics that are responsive to electric and light stimulation simultaneously.
Journal ArticleDOI
Metal to semiconductor transition in metallic transition metal dichalcogenides
TL;DR: In this paper, the electronic and magnetic properties of metallic transition metal dichalcogenides (mTMDCs) were tuned by 2D to 1D size confinement and the stability of the mTMDC monolayers and nanoribbons was demonstrated by the larger binding energy compared to the experimentally available semiconducting TMDCs.
Journal ArticleDOI
Ambient effects on photogating in MoS2 photodetectors.
Peize Han,Eli R Adler,Yijing Liu,Luke St. Marie,Abdel El Fatimy,Scott Melis,Edward Van Keuren,Paola Barbara +7 more
TL;DR: In this article, the influence of adsorbates on MoS2 photodetectors under ambient conditions, vacuum and illumination at different wavelengths was studied, and it was shown that the change in the molecular gating provided by the physisorbed molecules is the dominant contribution to the device photoresponse in ambient conditions.
Journal ArticleDOI
Efficient and reliable surface charge transfer doping of black phosphorus via atomic layer deposited MgO toward high performance complementary circuits
Wugang Liao,Lin Wang,Li Chen,Wei Wei,Zhe Zeng,Xuewei Feng,Li Huang,Wee Chong Tan,Xin Huang,Kah-Wee Ang,Chunxiang Zhu +10 more
TL;DR: It is suggested that surface charge transfer doping via MgO can be used as a promising technique towards high performance BP-based functional nanoelectronics.
References
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Journal ArticleDOI
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Atomically thin MoS2: a new direct-gap semiconductor
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