Two-dimensional bilayer MoS2 flakes with variable size of the upper layer grown by chemical vapor deposition

One-Step CVD Growth and Interlayer Coupling Characteristics of Twisted MoS2/MoS2/MoS2 Homotrilayers

“…Meanwhile, the frequency separation of E 2g and A 1g modes exhibits a remarkable increase from 20.7 to 24.5 cm −1 as the position toward point 3, as drawn in Figure 2d. Such a frequency separation can be attributed to the thickness increase from the monolayer to the trilayer, 20,23,25 suggesting the thickness of the single-layer at point 1, two-layer at point 2, and three-layer at point 3. In addition, position and intensity mappings of E 2g and A 1g modes from such a trilayered structure have been performed to further estimate the thickness distribution, as exhibited in Figure 2e−h.…”

Valley-Selective Polarization in Twisted Bilayer Graphene Controlled by a Counter-Rotating Bicircular Laser Field

“…Furthermore, recent research has established that electrons in two-dimensional hexagonal materials possess an additional degree of freedom, known as the valley pseudospin, which corresponds to extreme points on the electron band dispersion curve. Such electrons are commonly found in materials such as graphene [4], layered transition metal dichalcogenides [5,6], and Weyl semimetal systems [7][8][9]. For instance, the energy band structure of graphene features two unequal yet degenerate Dirac points on the Fermi surface of the first Brillouin zone (BZ), referred to as the K 1 and K 2 valleys.…”