  The effect of the presence of electron-phonon (e-ph) coupling in the SiC, GeC
and SnC hybrids is studied in the framework of the ab initio perturbation
theory. The electronic bang gap thermal dependence reveals a normal monotonic
decrease in the SiC and GeC semiconductors, whereas SnC exhibits an anomalous
behavior. The electron line widths were evaluated and the contributions of
acoustic and optical phonon modes to the imaginary part of the self-energy were
determined. It has been found that the e-ph scattering rates are globally
controlled by the out-of-plane acoustic transverse mode ZA in SiC while both ZA
and ZO are overriding in GeC. In SnC, the out-of-plane transverse optical mode
ZO is the most dominant. The relaxation lifetime of the photo-excited electrons
shows that the thermalization of the hot carrier occurs at 90 fs, 100 fs and
120 fs in SiC, GeC and SnC, respectively. The present study properly describes
the subpicosecond time scale after sunlight illumination using an approach that
requires no empirical data. The results make the investigated structures
suitable for providing low cost and high-performance optical communication and
monitoring applications using 2D materials.
