Interlayer interaction in 2H-MoTe2/hBN heterostructures
- 발행기관 서강대학교 일반대학원
- 지도교수 정현식
- 발행년도 2021
- 학위수여년월 2021. 8
- 학위명 석사
- 학과 및 전공 일반대학원 물리학과
- UCI I804:11029-000000066153
- 본문언어 영어
- 저작권 서강대학교 논문은 저작권보호를 받습니다.
초록/요약
2H-MoTe2 and hBN are two-dimension (2D) materials that have important contribution to optoelectronic devices. It is necessary to characterize heterostructures formed by vertically stacking these materials. In this word, interlayer vibrational modes in 2H-MoTe2/hBN heterostructures were investigated by low-frequency Raman spectroscopy. A series of low-frequency Raman modes are observed for MoTe2 thicknesses of 1 to 4 layers: the shear modes of MoTe2 persist in the heterostructure with no shift in the frequency, but the breathing modes show dramatic changes in the heterostructures. The number and the frequencies of the breathing modes do not depend on the twist angle between the two materials but strongly vary with the layer thicknesses of both MoTe2 and hBN layers. The breathing modes were observed for both resonant (1.96 eV) and non-resonant (2.41 eV) excitations. The breathing mode frequencies were analyzed by using the linear chain model, and the interfacial force constant between 2H-MoTe2 and hBN is estimated to be 3.77×1019 Nm-3.
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