  A study of the formation of excitons as a problem of two Dirac particles in a
gapped graphene layer and in two gapped graphene layers separated by a
dielectric is presented. In the low energy limit the separation of the
center-of-mass and relative motions is obtained. Analytical solutions for the
wave function and energy dispersion for both cases when electron and hole
interact via a Coulomb potential are found. It is shown that the energy
spectrum and the effective exciton mass are functions of the energy gaps as
well as interlayer separation in case of two layer gapped graphene.
