  We study formation and superfluidity of dipolar excitons in double layer
heterostructures formed by two transition metal dichalcogenide (TMDC)
atomically thin layers. Considering screening effects for an electron-hole
interaction via the harmonic oscillator approximation for the Keldysh
potential, the analytical expressions for the exciton energy spectrum and the
mean field critical temperature $T_{c}$ for the superfluidity are obtained. It
is shown that binding energies of A excitons are larger than for B excitons.
The mean field critical temperature for a two-component dilute exciton system
in a TMDC double layer is analyzed and shown that latter is an increasing
function of the factor $Q$, determined by the effective masses of A and B
excitons and their reduced mass. Comparison of the calculations for $T_{c}$
performed by employing the Coulomb and Keldysh interactions demonstrates the
importance of screening effects in TMDC.
