Enhanced Light Emission from the Ridge of Two-Dimensional InSe Flakes
- Rensselaer Polytechnic Institute, Troy, NY (United States); Harbin Institute of Technology (China)
- Rensselaer Polytechnic Institute, Troy, NY (United States)
- Rensselaer Polytechnic Institute, Troy, NY (United States); Shanghai Jiao Tong University (China)
- Institute of Physics, Academia Sinica, Taipei (Taiwan); National Taiwan University, Taipei (Taiwan)
- Harbin Institute of Technology (China)
InSe, a newly rediscovered two-dimensional (2D) semiconductor, possesses superior electrical and optical properties as a direct-band-gap semiconductor with high mobility from bulk to atomically thin layers and is drastically different from transition-metal dichalcogenides, in which the direct band gap only exists at the single-layer limit. However, absorption in InSe is mostly dominated by an out-of-plane dipole contribution, which results in the limited absorption of normally incident light that can only excite the in-plane dipole at resonance. To address this challenge, we have explored a unique geometric ridge state of the 2D flake without compromising the sample quality. Here we observed the enhanced absorption at the ridge over a broad range of excitation frequencies from photocurrent and photoluminescence (PL) measurements. In addition, we have discovered new PL peaks at low temperatures due to defect states on the ridge, which can be as much as ~60 times stronger than the intrinsic PL peak of InSe. Interestingly, the PL of the defects is highly tunable through an external electrical field, which can be attributed to the Stark effect of the localized defects. InSe ridges thus provide new avenues for manipulating light–matter interactions and defect engineering that are vitally crucial for novel optoelectronic devices based on 2D semiconductors.
- Research Organization:
- Rensselaer Polytechnic Inst., Troy, NY (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); US Air Force Office of Scientific Research (AFOSR); National Science Foundation (NSF); National Natural Science Foundation of China (NSFC)
- Grant/Contract Number:
- SC0002623; AC02-05CH11231; FA9550-18-1-0312; EFMA-1542798; 51572057
- OSTI ID:
- 1539426
- Journal Information:
- Nano Letters, Vol. 18, Issue 8; ISSN 1530-6984
- Publisher:
- American Chemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Manipulating Optical Absorption of Indium Selenide Using Plasmonic Nanoparticles
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journal | February 2020 |
Out-of-plane orientation of luminescent excitons in two-dimensional indium selenide
|
journal | September 2019 |
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