Control of biaxial strain in single-layer molybdenite using local thermal expansion of the substrate

Plechinger G, Castellanos-Gomez A, Buscema M, Van Der Zant HSJ, Steele GA, Kuc A, Heine T, Schueller C, Korn T (2015)

Publication Type: Journal article

Publication year: 2015

Journal

2D Materials IOP Science

Book Volume: 2

Article Number: A20

Journal Issue: 1

DOI: 10.1088/2053-1583/2/1/015006

Abstract

Single-layer MoS2 is a direct-gap semiconductor whose electronic band structure strongly depends on the strain applied to its crystal lattice. While uniaxial strain can be easily applied in a controlled way, e.g., by bending of a flexible substrate with the atomically thin MoS2 layer on top, experimental realization of biaxial strain is more challenging. Here, we exploit the large mismatch between the thermal expansion coefficients of MoS2 and a silicone-based substrate to apply a controllable biaxial tensile strain by heating the substrate with a focused laser. The effect of this biaxial strain is directly observable in optical spectroscopy as a redshift of the MoS2 photoluminescence.Wealso demonstrate the potential of this method to engineer more complex strain patterns by employing highly absorptive features on the substrate to achieve non-uniform heat profiles. By comparison of the observed redshift to strain-dependent band structure calculations, we estimate the biaxial strain applied by the siliconebased substrate to be up to 0.2%, corresponding to a band gap modulation of 105 meV per percentage of biaxial tensile strain.

Involved external institutions

Universität Regensburg DE Germany (DE) Delft University of Technology (TU Delft) NL Netherlands (NL) Jacobs University Bremen gGmbH DE Germany (DE)

How to cite

APA:

Plechinger, G., Castellanos-Gomez, A., Buscema, M., Van Der Zant, H.S.J., Steele, G.A., Kuc, A.,... Korn, T. (2015). Control of biaxial strain in single-layer molybdenite using local thermal expansion of the substrate. 2D Materials, 2(1). https://doi.org/10.1088/2053-1583/2/1/015006

MLA:

Plechinger, Gerd, et al. "Control of biaxial strain in single-layer molybdenite using local thermal expansion of the substrate." 2D Materials 2.1 (2015).

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