Binding energies of exciton complexes in transition metal dichalcogenide monolayers and effect of dielectric environment

Excitons, trions, biexcitons, and exciton-trion complexes in two-dimensional transition metal dichalcogenide sheets of ${\mathrm{MoS}}_{2}, {\mathrm{MoSe}}_{2}, {\mathrm{MoTe}}_{2}, {\mathrm{WS}}_{2}$, and ${\mathrm{WSe}}_{2}$ are studied by means of density functional theory and path-integral Monte Carlo method in order to accurately account for the particle-particle correlations. In addition, the effect of dielectric environment on the properties of these exciton complexes is studied by modify