Evolution of phonon and electronic structures of transition metal dichalcogenides as a function of large uniaxial strain

ORAL

Abstract

Monolayer transition metal dichalcogenides (TMD), like graphene, are highly stretchable materials. The application of uniaxial strain to semiconductor materials changes band gaps, effective masses and scattering mechanisms. Here, we present techniques by which large (several percent) controllable strain can be applied to the semiconducting TMD materials by using polymer encapsulation. Our versatile method allows for the application of both compressive and tensile strain. Using polarized Raman spectroscopy, we monitor the changes to the lattice structure and compare results to those expected from ab-initio theoretical calculations. Using photoluminescence measurements, we track the changes in the excitonic transitions in these materials and show that the optical response of two-dimensional semiconductors is highly tunable using uniaxial strain.

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Authors

  • Ali Dadgar

    Department of Mechanical Engineering, Columbia University, New York, USA

  • Abhay Pasupathy

    Columbia University, Department of Physics, Columbia University, New York, New York 10027, USA, Physics Department, Columbia University, New York, USA

  • Elton Santos

    School of Mathematics and Physics, Queen's University, Belfast, UK, School of Mathematics and Physics, BT7 1NN, School of Chemistry and Chemical Engineering, BT9 5AL, Queen's University Belfast, United Kingdom

  • Marcos Pimenta

    Department of Physics, UFMG, Belo Horizonte, Brazil, Universidade Federal de Minas Gerais

  • E.H. Yang

    Deparment of Mechanical Engineering, Stevens Institute of Technology, NJ, USA

  • Kyung Nam Kang

    Department of Mechanical Engineering, Stevens Institute of Technology, Department of Mechanical Engineering, Stevens Institute of Technology, NJ, USA

  • Declan Scullion

    School of Mathematics and Physics, Queen's University, Belfast, UK

  • Peter Rice

    School of Mathematics and Physics, Queen's University, Belfast, UK

  • Irving Herman

    Department of Applied physics and Applied Mathematics, Columbia University, Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA, Department of Applied Physics, Columbia University, New York, USA