  The rising interest in Dirac materials, condensed matter systems where
low-energy electronic excitations are described by the relativistic Dirac
Hamiltonian, entails a need for microscopic effective models to analytically
describe their transport properties. Specifically, for the study of quantum
transport, these effective models must take into account the effect of
atomic-scale interfaces and the presence of well-defined edges while
reproducing the correct band structure. We develop a general method to
analytically compute the microscopic Green's function of Dirac materials valid
for infinite, semi-infinite, and finite two-dimensional layers with zigzag or
armchair edge orientations. We test our method by computing the density of
states and scattering probabilities of germanene and some transition metal
dichalcogenides, obtaining simple analytical formulas. Our results provide a
useful analytical tool for the interpretation of transport experiments on Dirac
materials and could be extended to describe additional degrees of freedom like
extra layers, superconductivity, etc.
