Asymmetric 3D Elastic-Plastic Strain-Modulated Electron Energy Structure in Monolayer Graphene by Laser Shocking

Maithilee Motlag; Prashant Kumar; Kevin Y Hu; Shengyu Jin; Ji Li; Jiayi Shao; Xuan Yi; Yen-Hsiang Lin; Jenna C Walrath; Lei Tong; Xinyu Huang; Rachel S Goldman; Lei Ye; Gary J Cheng

doi:10.1002/adma.201900597

Asymmetric 3D Elastic-Plastic Strain-Modulated Electron Energy Structure in Monolayer Graphene by Laser Shocking

Adv Mater. 2019 May;31(19):e1900597. doi: 10.1002/adma.201900597. Epub 2019 Mar 29.

Authors

Maithilee Motlag¹, Prashant Kumar^{1

2

3}, Kevin Y Hu^{1

2

4}, Shengyu Jin^{1

2}, Ji Li^{1

2}, Jiayi Shao², Xuan Yi^{2

5}, Yen-Hsiang Lin⁶, Jenna C Walrath⁶, Lei Tong⁷, Xinyu Huang⁷, Rachel S Goldman^{6

8}, Lei Ye⁷, Gary J Cheng^{1

2

9}

Affiliations

¹ School of Industrial Engineering, Purdue University, West Lafayette, IN, 47907, USA.
² Birck Nanotechnology Centre, Purdue University, West Lafayette, IN, 47907, USA.
³ Department of Physics, Indian Institute of Technology Patna, Bihta Campus, Bihar, 801106, India.
⁴ Department of Mechanical and Aerospace Engineering, University at Buffalo, 240 Bell Hall, Buffalo, NY, 14260-4400, USA.
⁵ School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, 47907, USA.
⁶ Department of Physics, University of Michigan, Ann Arbor, MI, 48109, USA.
⁷ School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, China.
⁸ Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, 48109, USA.
⁹ School of Materials Engineering, Purdue University, West Lafayette, IN, 47907, USA.

PMID: 30924972
DOI: 10.1002/adma.201900597

Abstract

Graphene has a great potential to replace silicon in prospective semiconductor industries due to its outstanding electronic and transport properties; nonetheless, its lack of energy bandgap is a substantial limitation for practical applications. To date, straining graphene to break its lattice symmetry is perhaps the most efficient approach toward realizing bandgap tunability in graphene. However, due to the weak lattice deformation induced by uniaxial or in-plane shear strain, most strained graphene studies have yielded bandgaps <1 eV. In this work, a modulated inhomogeneous local asymmetric elastic-plastic straining is reported that utilizes GPa-level laser shocking at a high strain rate (dε/dt) ≈ 10⁶ -10⁷ s^-1 , with excellent formability, inducing tunable bandgaps in graphene of up to 2.1 eV, as determined by scanning tunneling spectroscopy. High-resolution imaging and Raman spectroscopy reveal strain-induced modifications to the atomic and electronic structure in graphene and first-principles simulations predict the measured bandgap openings. Laser shock modulation of semimetallic graphene to a semiconducting material with controllable bandgap has the potential to benefit the electronic and optoelectronic industries.

Keywords: bandgap engineering; optomechanical 3D straining; single-layer graphene.

Abstract

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