title: Precise and reversible band gap tuning in single-layer MoSe2 by uniaxial strain.
abstract: We present photoluminescence (PL) spectroscopy measurements of single-layer MoSe2 as a function of uniform uniaxial strain. A simple clamping and bending method is described that allows for application of uniaxial strain to layered, 2D materials with strains up to 1.1% without slippage. Using this technique, we find that the electronic band gap of single layer MoSe2 can be reversibly tuned by -27 ± 2 meV per percent of strain. This is in agreement with our density-functional theory calculations, which estimate a modulation of -32 meV per percent of strain, taking into account the role of deformation of the underlying substrate upon bending. Finally, due to its narrow PL spectra as compared with that of MoS2, we show that MoSe2 provides a more precise determination of small changes in strain making it the ideal 2D material for strain applications.
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands. j.o.island@tudelft.nl andres.castellanos@imdea.org.
authors.forename: Joshua O
authors.initials: JO
authors.lastname: Island
authors.affiliation: Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28779 Bremen, Germany and Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103 Leipzig, Germany.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Kuc
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands. j.o.island@tudelft.nl andres.castellanos@imdea.org.
authors.forename: Erik H
authors.initials: EH
authors.lastname: Diependaal
authors.affiliation: Institute of Physics, University of Münster and Center for Nanotechnology, D-48149 Münster, Germany.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Bratschitsch
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands. j.o.island@tudelft.nl andres.castellanos@imdea.org.
authors.forename: Herre S J
authors.initials: HS
authors.lastname: van der Zant
authors.affiliation: Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28779 Bremen, Germany and Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103 Leipzig, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Heine
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands. j.o.island@tudelft.nl andres.castellanos@imdea.org and Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia), Campus de Cantoblanco, E-28049 Madrid, Spain.
authors.forename: Andres
authors.initials: A
authors.lastname: Castellanos-Gomez