Table 2 Formation energy (Eform/eV atom−1), substitutional energy (Esubst/eV atom−), substitutional energy with vacancy defects (Esubst-V/eV atom−1), resulting lattice constant (a), lattice parameters (a, b, and c), volume (V), and relative volume expansion (ΔV) of the random and Janus-type MoS2−xSex phases at different concentrations of Se. Negative values of Eform, Eseg, and Eseg-V designate a thermodynamically favorable process.
Se at. % | Eform/eV atom−1 | Esubst/eV atom−1 | Esusbt-V/eV atom−1 | a/nm | a/nm | b/nm | c/nm | V/nm3 | ΔV |
|---|---|---|---|---|---|---|---|---|---|
Random MoS2−xSex | |||||||||
0.0 | – | – | – | 0.3167 | 1.2668 | 1.2668 | 1.2668 | 1.7345 | 0.0% |
4 | − 7.515 | 0.036 | 0.332 | 0.3174 | 1.270 | 1.270 | 1.254 | 1.750 | 0.92% |
8 | − 7.479 | 0.072 | 0.663 | 0.3182 | 1.273 | 1.273 | 1.259 | 1.766 | 1.81% |
16 | − 7.407 | 0.144 | 1.326 | 0.3196 | 1.279 | 1.279 | 1.270 | 1.797 | 3.49% |
33.3 | − 7.263 | 0.288 | 2.651 | 0.3227 | 1.291 | 1.291 | 1.285 | 1.855 | 6.49% |
Janus MoS2−xSex | |||||||||
4 | 8.572 | 16.123 | 16.419 | 3.1875 | 1.275 | 1.275 | 1.248 | 1.756 | 0.47% |
8 | 8.608 | 16.159 | 16.750 | 3.1948 | 1.278 | 1.278 | 1.253 | 1.770 | 1.78% |
16 | − 7.406 | 0.145 | 1.327 | 3.1968 | 1.279 | 1.279 | 1.266 | 1.792 | 3.33% |
33.3 | − 7.259 | 0.292 | 2.656 | 0.3229 | 1.292 | 1.292 | 1.275 | 1.842 | 5.84% |
