Local Strain Induced Band Gap Modulation and Photoluminescence Enhancement of Multilayer Transition Metal Dichalcogenides

The photocarrier relaxation between direct and indirect band gaps along the high symmetry K−Γ line in the Brillion zone reveals interesting electronic properties of the transition metal dichalcogenides (TMDs) multilayer films. In this study, we reported on the local strain engineering and tuning of an electronic band structure of TMDs multilayer films along the K−Γ line by artificially creating one-dimensional wrinkle structures. Significant photoluminescence (PL) intensity enhancement in conjunction with continuously tuned optical energy gaps was recorded at the high strain regions. A direct optical band gap along K–K points and an indirect optical gap along Γ–K points measured from the PL spectra of multilayer samples monotonically decreased as the strain increased, while the indirect band gap along Λ–Γ was unaffected owing to the same level of local strain in the range of 0%–2%. The experimental results of band gap tuning were in agreement with the density functional theory calculation results. Local s...

[1]  Jeongyong Kim,et al.  Spectroscopic Visualization of Grain Boundaries of Monolayer Molybdenum Disulfide by Stacking Bilayers. , 2015, ACS nano.

[2]  C. Battaglia,et al.  Strain-induced indirect to direct bandgap transition in multilayer WSe2. , 2014, Nano letters.

[3]  Magnetoelectric effects and valley-controlled spin quantum gates in transition metal dichalcogenide bilayers. , 2013, Nature communications.

[4]  Changgu Lee,et al.  Efficient Excitonic Photoluminescence in Direct and Indirect Band Gap Monolayer MoS2. , 2015, Nano letters.

[5]  W. Zhang 张,et al.  Electronic structures and elastic properties of monolayer and bilayer transition metal dichalcogenides MX2 (M = Mo, W; X = O, S, Se, Te): A comparative first-principles study , 2015, 1505.01640.

[6]  Origin of indirect optical transitions in few-layer MoS2, WS2, and WSe2. , 2013, Nano letters.

[7]  G. Ryu,et al.  On-stack two-dimensional conversion of MoS2 into MoO3 , 2016, 2008.03926.

[8]  Bennett B. Goldberg,et al.  Band Gap Engineering with Ultralarge Biaxial Strains in Suspended Monolayer MoS2. , 2016, Nano letters.

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

[10]  A. Castellanos-Gómez,et al.  Precise and reversible band gap tuning in single-layer MoSe2 by uniaxial strain. , 2015, Nanoscale.

[11]  J. Rogers,et al.  Quantum confinement effects in transferrable silicon nanomembranes and their applications on unusual substrates. , 2013, Nano letters.

[12]  Kan Wang,et al.  Lattice strain effects on the optical properties of MoS2 nanosheets , 2014, Scientific Reports.

[13]  F. Guinea,et al.  Strong Modulation of Optical Properties in Black Phosphorus through Strain-Engineered Rippling. , 2015, Nano letters.

[14]  T.-H. Cheng,et al.  Strain-enhanced photoluminescence from Ge direct transition , 2010 .

[15]  D. Duong,et al.  Confocal absorption spectral imaging of MoS2: optical transitions depending on the atomic thickness of intrinsic and chemically doped MoS2. , 2014, Nanoscale.

[16]  Junyong Kang,et al.  Strain-induced direct–indirect bandgap transition and phonon modulation in monolayer WS2 , 2015, Nano Research.

[17]  C. D. Walle,et al.  Effects of strain on band structure and effective masses in MoS$_2$ , 2012 .

[18]  F. Guinea,et al.  Strain engineering in semiconducting two-dimensional crystals , 2015, Journal of physics. Condensed matter : an Institute of Physics journal.

[19]  Keliang He,et al.  Orientation of luminescent excitons in layered nanomaterials. , 2013, Nature nanotechnology.

[20]  Fengnian Xia,et al.  Strong light–matter coupling in two-dimensional atomic crystals , 2014, Nature Photonics.

[21]  M. Arroyo,et al.  Understanding and strain-engineering wrinkle networks in supported graphene through simulations , 2014 .

[22]  L. Chu,et al.  Evolution of electronic structure in atomically thin sheets of WS2 and WSe2. , 2012, ACS nano.

[23]  Yong Ju Park,et al.  Graphene-based conformal devices. , 2014, ACS nano.

[24]  P. Ajayan,et al.  Optoelectronic crystal of artificial atoms in strain-textured molybdenum disulphide , 2015, Nature Communications.

[25]  Sefaattin Tongay,et al.  Thermally driven crossover from indirect toward direct bandgap in 2D semiconductors: MoSe2 versus MoS2. , 2012, Nano letters.

[26]  Gang Hee Han,et al.  Characterization of the structural defects in CVD-grown monolayered MoS2 using near-field photoluminescence imaging. , 2015, Nanoscale.

[27]  J. Shan,et al.  Experimental demonstration of continuous electronic structure tuning via strain in atomically thin MoS2. , 2013, Nano letters.

[28]  Hongzheng Chen,et al.  Graphene-like two-dimensional materials. , 2013, Chemical reviews.

[29]  Chen Wang,et al.  Analysis of tensile strain enhancement in Ge nano-belts on an insulator surrounded by dielectrics , 2013 .

[30]  Coskun Kocabas,et al.  Graphene-enabled electrically switchable radar-absorbing surfaces , 2015, Nature Communications.

[31]  Jingbo Li,et al.  Tuning the optical, magnetic, and electrical properties of ReSe2 by nanoscale strain engineering. , 2015, Nano letters.

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

[33]  Young Hee Lee,et al.  Biexciton Emission from Edges and Grain Boundaries of Triangular WS₂ Monolayers. , 2016, ACS nano.

[34]  Sefaattin Tongay,et al.  Elastic properties of chemical-vapor-deposited monolayer MoS2, WS2, and their bilayer heterostructures. , 2014, Nano letters.

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

[36]  Yong-Wei Zhang,et al.  Quasiparticle band structures and optical properties of strained monolayer MoS 2 and WS 2 , 2012, 1211.5653.

[37]  Francisco Guinea,et al.  Local strain engineering in atomically thin MoS2. , 2013, Nano letters.

[38]  Liangzhi Kou,et al.  Anisotropic Ripple Deformation in Phosphorene. , 2015, The journal of physical chemistry letters.