[20a-PA3-1~10] 4 JSAP-OSA Joint Symposia 2019 (Poster)

▼ [20a-PA3-10] Identification of stacking configurations in a few-layered-MoS₂ sample by low-frequency Raman spectroscopy

〇(D)Rhea Thankam Sam¹, Ryo Kato¹, Takayuki Umakoshi¹, Prabhat Verma¹ (1.Osaka University)

Keywords:2D materials, MoS2, Raman spectroscopy

Two-dimensional (2D) layered materials, such as MoS₂, are often used in electronic and optoelectronic devices as active media in the form of a few layers. The orientations of different layers and their stacking configurations alter the crystal symmetry, thereby modifying the band structure and the electronic properties of the device. Since MoS₂ has layer stacking, and layer number dependent properties, a thorough understanding of the stacking sequences and the number of layers is essential for a full exploration of their potential. Interlayer Raman modes, such as, shear and breathing modes that arise due to the in-plane and the out-of-plane vibrations of entire layers can characterize stacking configurations and determine the number of layers. Since these modes originate from the weak interlayer van der Waals interactions, they appear in the ultra-low-frequency range in the Raman spectrum. This research focuses on identifying different stacking configurations of MoS₂ layers using ultra-low-frequency Raman spectroscopy.