Stability, electronic and mechanical properties of chalcogen (Se and Te) monolayers

Abstract

By employing density functional theory, we have explored the stability and electronic and mechanical properties of chalcogen (Se and Te) monolayers.

Bonding, structure, and mechanical stability of 2D materials: the predictive power of the periodic table

“…[246][247][248] In the following, the thickness direction is defined as the z-direction, and the chain direction is defined as the y-direction for the chain-like and tetragonal phases, whereas for the rhombic phase the y-direction extends along the armchair direction, due to the loss of the original chain structure by reconstruction. 247 The space group, cohesive energy, lattice constants, bond length, corrugation, and layer thickness of the trigonal, 246,[248][249][250] tetragonal, 246,251,252 rhombic, 245,248,[252][253][254] and monoclinic 224,249 structures of selenene are presented in Table 12, along with the bonding information and structural properties of the trigonal, 247,250,255,256 tetragonal, 247,255 rhombic, [252][253][254][255] and monoclinic 249 structures of tellurene. This data makes possible a discussion of bonding-structure-performance relationships for these recently discovered 2D materials with novel structures deviating from previous hexagonal 2D materials.…”

InSe/Te van der Waals Heterostructure as a High-Efficiency Solar Cell from Computational Screening

“…The MX A (M = Al, Ga, In and X A = S, Se, Te) and X B (X B = Se, Te) monolayers, where the positions of the elements in the periodic table are shown in Figure 1 a, are crystallized in the space group of P63/mmc with a honeycomb hexagonal structure [ 30 , 43 ]. Table S1 lists the optimized lattice constant, bond length and band gaps for the monolayers, where the results are in good agreement with the previous reports [ 44 , 45 ].…”

“…Recently, the 1T-MoS 2 -like phase T -Se and α -Te were successfully obtained in the laboratory [ 28 , 29 ]. The III–VI monolayers and T -Se, α -Te are all P63/mmc lattice semiconductors with great optical properties and high carrier mobility [ 15 , 30 ]. Theoretically, the selenene and tellurene are evaluated as indirect band gaps of 1.16 and 1.11 eV [ 30 ], respectively, which may be converted to direct band gaps after the formation of vdW heterostructures [ 31 ].…”

“…The III–VI monolayers and T -Se, α -Te are all P63/mmc lattice semiconductors with great optical properties and high carrier mobility [ 15 , 30 ]. Theoretically, the selenene and tellurene are evaluated as indirect band gaps of 1.16 and 1.11 eV [ 30 ], respectively, which may be converted to direct band gaps after the formation of vdW heterostructures [ 31 ]. Therefore, it is highly desirable to build group III–VI/selenene and III–VI/tellurene vdW heterostructures, which are good candidates for the absorption layers for solar cell application.…”

Emerging low-dimensional materials for mid-infrared detection

“…The inter-planar spacings are measured to be 1.9 and 2.8 Å, which correspond to Te (1210) and (0001) planes respectively. In the 2D Te, the helical chains are arranged along a-axis with vdW forces into a quasi-2D plane geometry with bond-free surfaces [45,106,107]. The unique chiral-chain vdW structure, and its strong anisotropy originates from a large difference between interchains, with weak vdW interactions, and intrachains, with strong Te-Te covalent bonds [43,103,108,109].…”