Dielectric screening of excitons and trions in single-layer MoS2.

Photoluminescence (PL) properties of single-layer MoS2 are indicated to have strong correlations with the surrounding dielectric environment. Blue shifts of up to 40 meV of exciton or trion PL peaks were observed as a function of the dielectric constant of the environment. These results can be explained by the dielectric screening effect of the Coulomb potential; based on this, a scaling relationship was developed with the extracted electronic band gap and exciton and trion binding energies in good agreement with theoretical estimations. It was also observed that the trion/exciton intensity ratio can be tuned by at least 1 order of magnitude with different dielectric environments. Our findings are helpful to better understand the tightly bound exciton properties in strongly quantum-confined systems and provide a simple approach to the selective and separate generation of excitons or trions with potential applications in excitonic interconnects and valleytronics.

[1]  Jing Kong,et al.  Role of the seeding promoter in MoS2 growth by chemical vapor deposition. , 2014, Nano letters.

[2]  Jing Kong,et al.  Electronic transport and device prospects of monolayer molybdenum disulphide grown by chemical vapour deposition. , 2014, Nature communications.

[3]  Zhi-Xun Shen,et al.  Direct observation of the transition from indirect to direct bandgap in atomically thin epitaxial MoSe2. , 2014, Nature nanotechnology.

[4]  Linyou Cao,et al.  Many-body effects in valleytronics: direct measurement of valley lifetimes in single-layer MoS2. , 2014, Nano letters.

[5]  Aaron M. Jones,et al.  Electrically tunable excitonic light-emitting diodes based on monolayer WSe2 p-n junctions. , 2013, Nature nanotechnology.

[6]  Nils Scheuschner,et al.  Photoluminescence of freestanding single- and few-layerMoS2 , 2013, 1311.5824.

[7]  Andres Castellanos-Gomez,et al.  The effect of the substrate on the Raman and photoluminescence emission of single-layer MoS2 , 2013, Nano Research.

[8]  E. Malic,et al.  Analytical approach to excitonic properties of MoS2 , 2013, 1311.1045.

[9]  D. Jena,et al.  Charge Scattering and Mobility in Atomically Thin Semiconductors , 2013, 1310.7157.

[10]  J. Kong,et al.  Biexciton formation in monolayer MoS2 as observed by transient absorption spectroscopy , 2014 .

[11]  K. Thygesen,et al.  How dielectric screening in two-dimensional crystals affects the convergence of excited-state calculations: Monolayer MoS2 , 2013, 1311.1384.

[12]  S. Louie,et al.  Optical spectrum of MoS2: many-body effects and diversity of exciton states. , 2013, Physical review letters.

[13]  Arindam Ghosh,et al.  Graphene-MoS2 hybrid structures for multifunctional photoresponsive memory devices. , 2013, Nature nanotechnology.

[14]  J. Grossman,et al.  Defects activated photoluminescence in two-dimensional semiconductors: interplay between bound, charged, and free excitons , 2013, Scientific Reports.

[15]  A. M. van der Zande,et al.  Direct measurement of the thickness-dependent electronic band structure of MoS2 using angle-resolved photoemission spectroscopy. , 2013, Physical review letters.

[16]  Yuhei Miyauchi,et al.  Tunable photoluminescence of monolayer MoS₂ via chemical doping. , 2013, Nano letters.

[17]  Pablo Jarillo-Herrero,et al.  Intrinsic Electronic Transport Properties of High-Quality Monolayer and Bilayer MoS[subscript 2] , 2013 .

[18]  K. Tsukagoshi,et al.  Thickness-dependent interfacial Coulomb scattering in atomically thin field-effect transistors. , 2013, Nano letters.

[19]  Andras Kis,et al.  Ultrasensitive photodetectors based on monolayer MoS2. , 2013, Nature nanotechnology.

[20]  J. Coleman,et al.  Liquid Exfoliation of Layered Materials , 2013, Science.

[21]  L. Wirtz,et al.  Effect of spin-orbit interaction on the excitonic effects in single-layer, double-layer, and bulk MoS2 , 2013, 1306.4257.

[22]  Timothy C. Berkelbach,et al.  Theory of neutral and charged excitons in monolayer transition metal dichalcogenides , 2013, 1305.4972.

[23]  Jed I. Ziegler,et al.  Bandgap engineering of strained monolayer and bilayer MoS2. , 2013, Nano letters.

[24]  Madan Dubey,et al.  Large-Area 2-D Electronics: Materials, Technology, and Devices , 2013, Proceedings of the IEEE.

[25]  O. Kolosov,et al.  Optical investigation of the natural electron doping in thin MoS2 films deposited on dielectric substrates , 2013, Scientific Reports.

[26]  Dameng Liu,et al.  Solvatochromic effect on the photoluminescence of MoS₂ monolayers. , 2013, Small.

[27]  Hua Zhang,et al.  The chemistry of two-dimensional layered transition metal dichalcogenide nanosheets. , 2013, Nature chemistry.

[28]  M. Dresselhaus,et al.  Synthesis and transfer of single-layer transition metal disulfides on diverse surfaces. , 2013, Nano letters.

[29]  Daniel Wolverson,et al.  Raman-scattering measurements and first-principles calculations of strain-induced phonon shifts in monolayer MoS2 , 2013 .

[30]  B. Radisavljevic,et al.  Mobility engineering and a metal-insulator transition in monolayer MoS₂. , 2013, Nature materials.

[31]  Huili Grace Xing,et al.  Exciton dynamics in suspended monolayer and few-layer MoS₂ 2D crystals. , 2013, ACS nano.

[32]  P. Avouris,et al.  Electroluminescence in single layer MoS2. , 2012, Nano letters.

[33]  Aaron M. Jones,et al.  Electrical control of neutral and charged excitons in a monolayer semiconductor , 2012, Nature Communications.

[34]  J. Shan,et al.  Tightly bound trions in monolayer MoS2. , 2012, Nature materials.

[35]  A. Radenović,et al.  Ultrasensitive photodetectors based on , 2013 .

[36]  A. Krasheninnikov,et al.  Effects of confinement and environment on the electronic structure and exciton binding energy of MoS2 from first principles , 2012 .

[37]  J. Kong,et al.  Large-scale 2D electronics based on single-layer MoS2 grown by chemical vapor deposition , 2012, 2012 International Electron Devices Meeting.

[38]  Xiaofeng Qian,et al.  Strain-engineered artificial atom as a broad-spectrum solar energy funnel , 2012, Nature Photonics.

[39]  Qing Hua Wang,et al.  Electronics and optoelectronics of two-dimensional transition metal dichalcogenides. , 2012, Nature nanotechnology.

[40]  A. Ramasubramaniam.  Large excitonic effects in monolayers of molybdenum and tungsten dichalcogenides , 2012 .

[41]  J. Kong,et al.  Integrated Circuits Based on Bilayer MoS , 2012 .

[42]  K. Tsukagoshi,et al.  Quantitative Raman spectrum and reliable thickness identification for atomic layers on insulating substrates. , 2012, ACS nano.

[43]  A. Javey,et al.  High-performance single layered WSe₂ p-FETs with chemically doped contacts. , 2012, Nano letters.

[44]  Keliang He,et al.  Control of valley polarization in monolayer MoS2 by optical helicity. , 2012, Nature nanotechnology.

[45]  Walter R. L. Lambrecht,et al.  Quasiparticle band structure calculation of monolayer, bilayer, and bulk MoS 2 , 2012 .

[46]  B. Chakraborty,et al.  Symmetry-dependent phonon renormalization in monolayer MoS2transistor , 2012, Physical Review B.

[47]  Bin Wang,et al.  Probing charge scattering mechanisms in suspended graphene by varying its dielectric environment , 2012, Nature Communications.

[48]  Lain‐Jong Li,et al.  Synthesis of Large‐Area MoS2 Atomic Layers with Chemical Vapor Deposition , 2012, Advanced materials.

[49]  Wang Yao,et al.  Valley polarization in MoS2 monolayers by optical pumping. , 2012, Nature nanotechnology.

[50]  D. Weiss,et al.  Low‐temperature photoluminescence of oxide‐covered single‐layer MoS2 , 2011, 1112.3747.

[51]  J. Kong,et al.  1 Integrated Circuits Based on Bilayer MoS 2 Transistors , 2012 .

[52]  Branimir Radisavljevic,et al.  Integrated circuits and logic operations based on single-layer MoS2. , 2011, ACS nano.

[53]  A. Radenović,et al.  Single-layer MoS2 transistors. , 2011, Nature nanotechnology.

[54]  J. Shan,et al.  Atomically thin MoS₂: a new direct-gap semiconductor. , 2010, Physical review letters.

[55]  T. Mizutani,et al.  Environmental Effects on Photoluminescence of Single-Walled Carbon Nanotubes , 2010 .

[56]  A. Splendiani,et al.  Emerging Photoluminescence in Monolayer , 2010 .

[57]  V. Stojanović,et al.  Optical switching: Excitonic interconnects , 2009 .

[58]  Yuyuan Tian,et al.  Dielectric screening enhanced performance in graphene FET. , 2009, Nano letters.

[59]  B. Goldberg,et al.  Scaling of exciton binding energy with external dielectric function in carbon nanotubes , 2007, 0707.1888.

[60]  A. Zunger,et al.  Lifetime and polarization of the radiative decay of excitons, biexcitons, and trions in CdSe nanocrystal quantum dots , 2007 .

[61]  K. Novoselov,et al.  Two-dimensional atomic crystals. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[62]  J. Tersoff,et al.  Scaling of excitons in carbon nanotubes. , 2004, Physical review letters.

[63]  Kulik,et al.  Dielectric enhancement of excitons in near-surface quantum wells. , 1996, Physical review. B, Condensed matter.

[64]  Yang,et al.  Analytic solution of a two-dimensional hydrogen atom. I. Nonrelativistic theory. , 1991, Physical review. A, Atomic, molecular, and optical physics.

[65]  Takagahara,et al.  Excitonic and nonlinear-optical properties of dielectric quantum-well structures. , 1989, Physical review. B, Condensed matter.