TY - JOUR
T1 - Understanding Interlayer Coupling in TMD-hBN Heterostructure by Raman Spectroscopy
AU - Ding, Li
AU - Ukhtary, Muhammad Shoufie
AU - Chubarov, Mikhail
AU - Choudhury, Tanushree H.
AU - Zhang, Fu
AU - Yang, Rui
AU - Zhang, Ao
AU - Fan, Jonathan A.
AU - Terrones, Mauricio
AU - Redwing, Joan M.
AU - Yang, Teng
AU - Li, Mingda
AU - Saito, Riichiro
AU - Huang, Shengxi
N1 - Funding Information:
Manuscript received May 3, 2018; revised June 3, 2018; accepted June 9, 2018. Date of publication July 10, 2018; date of current version September 20, 2018. The work of L. Ding and S. Huang was supported by the Electrical Engineering Department and the Materials Research Institute, The Pennsylvania State University. The work of M. S. Ukhtary and R. Saito was supported by JSPS KAKENHI under Grants JP18J10199 and JP18H01810. The work of M. Chubarov, T. H. Choudhury, and J. M. Redwing was supported by The Pennsylvania State University 2-D Crystal Consortium—Materials Innovation Platform (2DCC-MIP) under NSF Cooperative Agreement DMR-1539916. The work of F. Zhang and M. Terrones was supported by the National Science Foundation through the I/UCRC Center for Atomically Thin Multifunctional Coatings (ATOMIC) under Grant IIP-1540018. The work of R. Yang and J. A. Fan was supported by the Air Force Office of Scientific Research Multidisciplinary University Research Initiative (MURI) under Award FA9550-16-1-0031. The work of T. Yang was supported in part by the National Key Program of China under Grant 2017YFA0206301 and in part by the Major Program of Aerospace Advanced Manufacturing Technology Research Foundation NSFC and CASC, China, under Grant U1537204. The review of this paper was arranged by Editor S. Das. (Corresponding author: Shengxi Huang.) L. Ding and S. Huang are with the Electrical Engineering Department, The Pennsylvania State University, University Park, PA 16802 USA (e-mail: sjh5899@psu.edu).
PY - 2018/10
Y1 - 2018/10
N2 - In 2-D van der Waals heterostructures, interactions between atomic layers dramatically change the vibrational properties of the hybrid system and demonstrate several interesting phenomena that are absent in individual materials. In this paper, we have investigated the vibrational properties of the heterostructure between transition metal dichalcogenide (TMD) and hexagonal boron nitride (hBN) on gold film at low- and high-frequency ranges by Raman spectroscopy. Nineteen Raman modes have been observed from the sample, including a new interlayer coupling mode at 28.8 cm-1. Compared to reported experimental results of tungsten disulfide (WS2) on SiO2/Si substrates, the Raman spectrum for WS2 on hBN/Au emerges a blue shift of about 8 cm-1. Furthermore, a remarkable enhancement of Raman intensity can be obtained when tuning hBN thickness in the heterostructure. Through systematic first-principles calculations, numerical simulations, and analytical calculations, we find that the 28.8 cm-1 mode originates from the shearing motion between monolayer TMD and hBN layers. In addition, the gold substrate and hBN layers form an optical cavity and the cavity interference effects enhance the obtained Raman intensity. This paper demonstrates the novel vibrational modes of 2-D van der Waals heterostructure as an effective tool to characterize a variety of such heterostructures and reveals a new method to enhance the Raman response of 2-D materials.
AB - In 2-D van der Waals heterostructures, interactions between atomic layers dramatically change the vibrational properties of the hybrid system and demonstrate several interesting phenomena that are absent in individual materials. In this paper, we have investigated the vibrational properties of the heterostructure between transition metal dichalcogenide (TMD) and hexagonal boron nitride (hBN) on gold film at low- and high-frequency ranges by Raman spectroscopy. Nineteen Raman modes have been observed from the sample, including a new interlayer coupling mode at 28.8 cm-1. Compared to reported experimental results of tungsten disulfide (WS2) on SiO2/Si substrates, the Raman spectrum for WS2 on hBN/Au emerges a blue shift of about 8 cm-1. Furthermore, a remarkable enhancement of Raman intensity can be obtained when tuning hBN thickness in the heterostructure. Through systematic first-principles calculations, numerical simulations, and analytical calculations, we find that the 28.8 cm-1 mode originates from the shearing motion between monolayer TMD and hBN layers. In addition, the gold substrate and hBN layers form an optical cavity and the cavity interference effects enhance the obtained Raman intensity. This paper demonstrates the novel vibrational modes of 2-D van der Waals heterostructure as an effective tool to characterize a variety of such heterostructures and reveals a new method to enhance the Raman response of 2-D materials.
KW - 2-D material
KW - Raman enhancement
KW - interference effect
KW - low-frequency (LF) vibration
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U2 - 10.1109/TED.2018.2847230
DO - 10.1109/TED.2018.2847230
M3 - Article
AN - SCOPUS:85049792725
VL - 65
SP - 4059
EP - 4067
JO - IEEE Transactions on Electron Devices
JF - IEEE Transactions on Electron Devices
SN - 0018-9383
IS - 10
M1 - 8409293
ER -