  We investigate the thermoelectric properties of ${\beta}$-FeSi$_{\text2}$
using first principles electronic structure and Boltzmann transport
calculations. We report a high thermopower for both \textit{p}- and
\textit{n}-type ${\beta}$-FeSi$_{\text2}$ over a wide range of carrier
concentration and in addition find the performance for \textit{n}-type to be
higher than for the \textit{p}-type. Our results indicate that, depending upon
temperature, a doping level of 3$\times10{^{20}}$ - 2$\times10{^{21}}$
cm${^{-3}}$ may optimize the thermoelectric performance.
