Using electrostatic doping to control structural phases in monolayer MoTe2

ORAL

Abstract

Monolayers of transition-metal dichalcogenides (TMDs) exhibit numerous crystal phases with distinct structures, symmetries and physical properties. Exploring the physics of transitions between these different structural phases in two dimensions may provide a means of switching material properties, with implications for potential applications. Structural phase transitions in TMDs have so far been induced by thermal or chemical means; purely electrostatic control over crystal phases through electrostatic doping was recently proposed, but has not yet been realized. Here we report first experimental demonstration that electrostatic doping could drive phase transition between the hexagonal and monoclinic phases of monolayer molybdenum ditelluride (MoTe2). Such transition is accompanied with hysteresis measured in Raman and Second Harmonic Generation. Polarization-resolved spectroscopies reveal crystal orientation before and after phase transition. It potentially bridges unique properties in monolayer materials such as valley degree of freedom, Ising pairing and topological transport. Such an unprecedented electrostatic driven structural phase transition opens new door for applications like electronic memory and low power switching.

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Presenters

  • Ying Wang

    UC berkeley

Authors

  • Ying Wang

    UC berkeley

  • Jun Xiao

    Univ of California - Berkeley, University of California - Berkeley, UC berkeley

  • Hanyu Zhu

    Univ of California - Berkeley, University of California - Berkeley, UC berkeley

  • Yao Li

    Stanford University

  • Yousif Alsaid

    UC berkeley

  • King Yan Fong

    UC berkeley, University of California at Berkeley

  • Yao Zhou

    Stanford University, Materials Sciences and Engineering, Stanford

  • Siqi Wang

    UC berkeley, University of California at Berkeley

  • Wu Shi

    UC Berkeley and LBNL, UC berkeley, Univ of California - Berkeley

  • Yuan Wang

    Univ of California - Berkeley, University of California - Berkeley, UC berkeley, University of California at Berkeley

  • Alex Zettl

    UC Berkeley and LBNL, UC berkeley, Univ of California - Berkeley, Physics, UC Berkeley, Physics, University of California, Berkeley, University of California at Berkeley, Physics, University of California - Berkeley, Department of Physics, Univ of California - Berkeley

  • Evan Reed

    Stanford University, Stanford Univ, Materials Sciences and Engineering, Stanford

  • Xiang Zhang

    Univ of California - Berkeley, University of California - Berkeley, UC berkeley, University of California at Berkeley