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Hung NT, Zhang K, Van Thanh V, Guo Y, Puretzky AA, Geohegan DB, Kong J, Huang S, Saito R. Nonlinear Optical Responses of Janus MoSSe/MoS 2 Heterobilayers Optimized by Stacking Order and Strain. ACS NANO 2023; 17:19877-19886. [PMID: 37643404 DOI: 10.1021/acsnano.3c04436] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Nonlinear optical responses in second harmonic generation (SHG) of van der Waals heterobilayers, Janus MoSSe/MoS2, are theoretically optimized as a function of strain and stacking order by adopting an exchange-correlation hybrid functional and a real-time approach in first-principles calculation. We find that the calculated nonlinear susceptibility, χ(2), in AA stacking (550 pm/V) becomes three times as large as AB stacking (170 pm/V) due to the broken inversion symmetry in the AA stacking. The present theoretical prediction is compared with the observed SHG spectra of Janus MoSSe/MoS2 heterobilayers, in which the peak SHG intensity of AA stacking becomes four times as large as AB stacking. Furthermore, a relatively large, two-dimensional strain (4%) that breaks the C3v point group symmetry of the MoSSe/MoS2, enhances calculated χ(2) values for both AA (900 pm/V) and AB (300 pm/V) stackings 1.6 times as large as that without strain.
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Affiliation(s)
- Nguyen Tuan Hung
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai 980-8578, Japan
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| | - Kunyan Zhang
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States
| | - Vuong Van Thanh
- School of Mechanical Engineering, Hanoi University of Science and Technology, Hanoi 100000, Viet Nam
| | - Yunfan Guo
- Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Alexander A Puretzky
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - David B Geohegan
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Jing Kong
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Shengxi Huang
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States
| | - Riichiro Saito
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
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Basu N, Kumar R, Manikandan D, Ghosh Dastidar M, Hedge P, Nayak PK, Bhallamudi VP. Strain relaxation in monolayer MoS 2 over flexible substrate. RSC Adv 2023; 13:16241-16247. [PMID: 37266495 PMCID: PMC10230350 DOI: 10.1039/d3ra01381b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 05/14/2023] [Indexed: 06/03/2023] Open
Abstract
In this communication, we demonstrate uniaxial strain relaxation in monolayer (1L) MoS2 transpires through cracks in both single and double-grain flakes. Chemical vapour deposition (CVD) grown 1L MoS2 has been transferred onto polyethylene terephthalate (PET) and poly(dimethylsiloxane) (PDMS) substrates for low (∼1%) and high (1-6%) strain measurements. Both Raman and photoluminescence (PL) spectroscopy revealed strain relaxation via cracks in the strain regime of 4-6%. In situ optical micrographs show the formation of large micron-scale cracks along the strain axis and ex situ atomic force microscopy (AFM) images reveal the formation of smaller lateral cracks due to the strain relaxation. Finite element simulation has been employed to estimate the applied strain efficiency as well as to simulate the strain distribution for MoS2 flakes. The present study reveals the uniaxial strain relaxation mechanism in 1L MoS2 and paves the way for exploring strain relaxation in other transition metal dichalcogenides (TMDCs) as well as their heterostructures.
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Affiliation(s)
- Nilanjan Basu
- Department of Physics, Indian Institute of Technology Madras Chennai 600 036 India
- 2D Materials Research and Innovation Group, Indian Institute of Technology Madras Chennai 600 036 India
| | - Ravindra Kumar
- Department of Physics, Indian Institute of Technology Madras Chennai 600 036 India
- 2D Materials Research and Innovation Group, Indian Institute of Technology Madras Chennai 600 036 India
| | - D Manikandan
- Department of Physics, Indian Institute of Technology Madras Chennai 600 036 India
- 2D Materials Research and Innovation Group, Indian Institute of Technology Madras Chennai 600 036 India
- Micro Nano and Bio-Fluidics Group, Indian Institute of Technology Madras Chennai 600 036 India
| | - Madhura Ghosh Dastidar
- Department of Physics, Indian Institute of Technology Madras Chennai 600 036 India
- 2D Materials Research and Innovation Group, Indian Institute of Technology Madras Chennai 600 036 India
- Quantum Center of Excellence for Diamond and Emerging Materials (QuCenDiEM) Group, Departments of Physics and Electrical Engineering, Indian Institute of Technology Madras Chennai 600036 India
| | - Praveen Hedge
- Department of Physics, Indian Institute of Technology Madras Chennai 600 036 India
- Quantum Center of Excellence for Diamond and Emerging Materials (QuCenDiEM) Group, Departments of Physics and Electrical Engineering, Indian Institute of Technology Madras Chennai 600036 India
| | - Pramoda K Nayak
- Department of Physics, Indian Institute of Technology Madras Chennai 600 036 India
- 2D Materials Research and Innovation Group, Indian Institute of Technology Madras Chennai 600 036 India
- Micro Nano and Bio-Fluidics Group, Indian Institute of Technology Madras Chennai 600 036 India
- Centre for Nano and Material Sciences, Jain (Deemed-to-be University) Jain Global Campus, Kanakapura Bangalore Karnataka 562112 India
| | - Vidya Praveen Bhallamudi
- Department of Physics, Indian Institute of Technology Madras Chennai 600 036 India
- Quantum Center of Excellence for Diamond and Emerging Materials (QuCenDiEM) Group, Departments of Physics and Electrical Engineering, Indian Institute of Technology Madras Chennai 600036 India
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