  In this paper, we have performed first principles calculations to study
optoelectronic, thermodynamic and transport properties of Fe2TiGe using density
functional theory (DFT). The semi-classical Boltzmann transport theory is used
to investigate transport properties. The calculated energy bands indicate that
Fe2TiGe is an indirect band gap semiconductor with band gap 0.734 eV for TB-mBJ
functional. Fe-3d and Ti-3d orbitals have the dominant contributions to the
density of states due to strong hybridization between them. The maximum value
of absorption coefficient is found to be 224x10^4 cm-1 in the ultraviolet
region. It is found that the static refractive index of Fe2TiGe is 5.18 which
is very close to that of Ge and much higher than that of GaAs. The obtained
refractive index implies that Fe2TiGe is a potential optical material that can
be used in optical devices such as photonic crystal, wave guides and solar
cells. The Debye temperature at ambient condition is 570 K and decreases slowly
with temperature. The Gruneisen parameter at ambient pressure and 300 K is 2.1
and slightly higher than that of PbTe (1.5). The calculated Seebeck coefficient
and power factor at 300 K using TB-mBJ functional are 271x10^-6 VK^-1 and
5.9x10^10 Wcm^-1K^-2, respectively. Therefore, the calculated optoelectronic
properties implies that Fe2TiGe is a potential candidate for photovoltaic
device applications.
