Journal ArticleDOI
Efficient Excitonic Photoluminescence in Direct and Indirect Band Gap Monolayer MoS2
Alexander Steinhoff,Ji-Hee Kim,Frank Jahnke,Malte Rösner,Dai-Sik Kim,Chanwoo Lee,Gang Hee Han,Mun Seok Jeong,Tim O. Wehling,Christopher Gies +9 more
TLDR
The large exciton binding energy in MoS2 enables two distinctly different excitation methods: above-band gap excitation and quasi-resonant excitation of excitonic resonances below the single-particle band gap.Abstract:
We discuss the photoluminescence (PL) of semiconducting transition metal dichalcogenides on the basis of experiments and a microscopic theory The latter connects ab initio calculations of the single-particle states and Coulomb matrix elements with a many-body description of optical emission spectra For monolayer MoS2, we study the PL efficiency at the excitonic A and B transitions in terms of carrier populations in the band structure and provide a quantitative comparison to an (In)GaAs quantum well-structure Suppression and enhancement of PL under biaxial strain is quantified in terms of changes in the local extrema of the conduction and valence bands The large exciton binding energy in MoS2 enables two distinctly different excitation methods: above-band gap excitation and quasi-resonant excitation of excitonic resonances below the single-particle band gap The latter case creates a nonequilibrium distribution of carriers predominantly in the K-valleys, which leads to strong emission from the A-exciton transition and a visible B-peak even if the band gap is indirect For above-band gap excitation, we predict a strongly reduced emission intensity at comparable carrier densities and the absence of B-exciton emission The results agree well with PL measurements performed on monolayer MoS2 at excitation wavelengths of 405 nm (above) and 532 nm (below the band gap)read more
Citations
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Journal ArticleDOI
Colloquium : Excitons in atomically thin transition metal dichalcogenides
Gang Wang,Alexey Chernikov,Mikhail M. Glazov,Tony F. Heinz,Xavier Marie,Thierry Amand,Bernhard Urbaszek +6 more
TL;DR: In this article, the authors reviewed recent progress in understanding of the excitonic properties in monolayer transition metal dichalcogenides (TMDs) and future challenges are laid out.
Journal ArticleDOI
Band Gap Engineering with Ultralarge Biaxial Strains in Suspended Monolayer MoS2.
David Lloyd,Xinghui Liu,Jason Christopher,Lauren Cantley,Anubhav Wadehra,Brian L. Kim,Bennett B. Goldberg,Anna K. Swan,J. Scott Bunch +8 more
TL;DR: The continuous and reversible tuning of the optical band gap of suspended monolayer MoS2 membranes is demonstrated by as much as 500 meV by applying very large biaxial strains and evidence for the strain tuning of higher level optical transitions is reported.
Journal ArticleDOI
2D materials advances: From large scale synthesis and controlled heterostructures to improved characterization techniques, defects and applications
Zhong Lin,Amber McCreary,Natalie Briggs,Shruti Subramanian,Kehao Zhang,Yifan Sun,Xufan Li,Nicholas J. Borys,Hongtao Yuan,Susan K. Fullerton-Shirey,Alexey Chernikov,Alexey Chernikov,Hui Zhao,Stephen McDonnell,Aaron M. Lindenberg,Kai Xiao,Brian J. Le Roy,Marija Drndic,James C. M. Hwang,Jiwoong Park,Manish Chhowalla,Raymond E. Schaak,Ali Javey,Ali Javey,Mark C. Hersam,Joshua A. Robinson,Mauricio Terrones +26 more
TL;DR: Lin et al. as mentioned in this paper reviewed the most recent breakthrough discoveries as well as emerging opportunities and remaining challenges in the field of 2D materials, including transition metal dichalcogenides, mono-elemental 2D sheets, and several carbide-and nitride-based materials.
Journal ArticleDOI
Excitonic linewidth and coherence lifetime in monolayer transition metal dichalcogenides.
Malte Selig,Gunnar Berghäuser,Archana Raja,Philipp Nagler,Christian Schüller,Tony F. Heinz,Tobias Korn,Alexey Chernikov,Alexey Chernikov,Ermin Malic,Andreas Knorr +10 more
TL;DR: It is shown that the excitonic coherence lifetime is determined by phonon-induced intravalley scattering and intervalley scattering into dark exciton states, and in particular, in WS2, exciton relaxation processes involving phonon emission into lower-lying dark states that are operative at all temperatures.
Journal ArticleDOI
Long-Lived Direct and Indirect Interlayer Excitons in van der Waals Heterostructures
Bastian Miller,Bastian Miller,Alexander Steinhoff,Borja Pano,Julian Klein,Julian Klein,Frank Jahnke,Alexander W. Holleitner,Alexander W. Holleitner,Ursula Wurstbauer,Ursula Wurstbauer +10 more
TL;DR: The observation of a doublet structure in the low-temperature photoluminescence of interlayer excitons in heterostructure consisting of monolayer MoSe2 and WSe2 provides fundamental insights into long-lived interlayer states in van der Waals heterostructures with possible bosonic many-body interactions.
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
Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set
Georg Kresse,Jürgen Furthmüller +1 more
TL;DR: A detailed description and comparison of algorithms for performing ab-initio quantum-mechanical calculations using pseudopotentials and a plane-wave basis set is presented in this article. But this is not a comparison of our algorithm with the one presented in this paper.
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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.
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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.
Journal ArticleDOI
Emerging Photoluminescence in Monolayer MoS2
Andrea Splendiani,Liang Sun,Yuanbo Zhang,Tianshu Li,Jonghwan Kim,Chi-Yung Chim,Giulia Galli,Feng Wang,Feng Wang +8 more
TL;DR: This observation shows that quantum confinement in layered d-electron materials like MoS(2), a prototypical metal dichalcogenide, provides new opportunities for engineering the electronic structure of matter at the nanoscale.