Modulation of band gap and optical response of layered MoX2 (X = S, Se, Te) for electronic and optoelectronic applications

Defect and interface/surface engineering synergistically modulated electron transfer and nonlinear absorption properties in MoX2 (X = Se, S, Te)@ZnO heterojunction

“…48 Thirdly, the semi-local functional difference of DFT will also lead to the underestimation of the theoretical bandgap. 60 As shown in Fig. S3(c), † no intermediate bandgap state was observed in the calculated DOS, indicating that the interlayer interaction between MoX 2 is very weak and there are no interfacial covalent bonds.…”

Role of defect engineering in revealing the electronic and sensing applications of Janus WSSe monolayer

“…Further, we have calculated the cohesive energy 57 ( E c ) to confirm the dynamic stability of the pristine Janus WSSe monolayer and formation energy 26 ( E f ) for chalcogen vacancy defected WSSe monolayer using the formulae: E c = ( E WSSe − E W − E S − E Se )/ N where, E WSSe , E W , E S and E Se present the total energy of the WSSe monolayer, energies of isolated W, S, and Se atoms, respectively, and N denotes the total number of atoms. E f = E defected − E pristine + E S/Se where, E defected , E pristine and E S/Se demonstrate the total energy of the chalcogen vacancy defected WSSe monolayer, the total energy of the pristine WSSe monolayer, and the energy of the isolated chalcogen atom S/Se, respectively.…”

“…The dielectric function is termed ε ( ω ) = ε 1 ( ω ) + i ε 2 ( ω ) where ε 2 ( ω ) refers to the imaginary part and ε 1 ( ω ) is a real part of the dielectric function, which has been calculated using the Kramers–Kronig transformation. 64 The absorption coefficient I (ω) is expressed as: 57 where, is the relative dielectric function ε ( ω ).…”

Selective and sensitive toxic gas-sensing mechanism in a 2D Janus MoSSe monolayer

“…The cohesive energy was described to verify the dynamic stability of the 2D material. After structural optimization, the cohesive energy per atom was determined using the formula for the pristine MoSSe monolayer: 10 E c = ( E MoSSe − E Mo − E S − E Se )/ N where E MoSSe , E Mo , E S and E Se are the total energy of the MoSSe monolayer, and energies of the isolated Mo, S and Se atoms, respectively, and N is the total number of atoms.…”

“…As an inspiration, the descendants of graphene were investigated, 7 with ultrathin and flexible transition metal dichalcogenides (TMDCs) receiving the most attention from the scientific community by overcoming the challenging issue of the tuning of the electronic band gap. [8][9][10] Except for 2D TMDCs, a wide spectrum of 2D materials, such as transition metal oxides, including titania-and perovskite-based oxides, 11 hexagonal boron nitride (h-BN), 12 germanene, 13 silicene, 14 arsenene 15 and MXenes (2D carbides/nitrides), 16,17 have been explored as new backbones with huge potential applications in the recent era. However, within the last decade, an emergent class of 2D layered materials has been shaped in a new form of a Janus structure as a counterpart to the heterostructure.…”