Journal
2D MATERIALS
Volume 5, Issue 2, Pages -Publisher
IOP PUBLISHING LTD
DOI: 10.1088/2053-1583/aaa6eb
Keywords
2D materials; flexible optoelectronics; strain; band structure engineering; InSe
Categories
Funding
- National Natural Science Foundation of China [51572057]
- Center for Future Energy Systems (CFES), a New York State Center for Advanced Technology at RN
- National Science Foundation [DMR-1508412]
- Micro and Nanofabrication Clean Room (MNCR)
- Rensselaer Polytechnic Institute
- Howard Isermann Fellowship from the Department of Chemical and Biological Engineering of Rensselaer Polytechnic Institute
- Theory of Materials Program at the Lawrence Berkeley National Laboratory through the Office of Basic Energy Sciences, US Department of Energy [DE-AC02-05CH11231]
Ask authors/readers for more resources
InSe, a member of the layered materials family, is a superior electronic and optical material which retains a direct bandgap feature from the bulk to atomically thin few-layers and high electronic mobility down to a single layer limit. We, for the first time, exploit strain to drastically modify the bandgap of two-dimensional (2D) InSe nanoflakes. We demonstrated that we could decrease the bandgap of a few-layer InSe flake by 160 meV through applying an in-plane uniaxial tensile strain to 1.06% and increase the bandgap by 79 meV through applying an in-plane uniaxial compressive strain to 0.62%, as evidenced by photoluminescence (PL) spectroscopy. The large reversible bandgap change of similar to 239 meV arises from a large bandgap change rate (bandgap strain coefficient) of fewlayer InSe in response to strain, similar to 154 meV/% for uniaxial tensile strain and similar to 140 meV/% for uniaxial compressive strain, representing the most pronounced uniaxial strain-induced bandgap strain coefficient experimentally reported in 2D materials. We developed a theoretical understanding of the strain-induced bandgap change through first-principles DFT and GW calculations. We also confirmed the bandgap change by photoconductivity measurements using excitation light with different photon energies. The highly tunable bandgap of InSe in the infrared regime should enable a wide range of applications, including electro-mechanical, piezoelectric and optoelectronic devices.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available