The importance of the future development of materials for use in low-temperature thermoelectric refrigeration devices is discussed. Specifically, results are presented on an interesting class of materials called pentatellurides, ${\mathrm{HfTe}}_{5}$ and ${\mathrm{ZrTe}}_{5},$ which have shown promising low-temperature thermoelectric properties $(100\mathrm{K}lTl250\mathrm{K}).$ Substitutional doping occurs both on the metal site as ${\mathrm{Hf}}_{1\ensuremath{-}x}{\mathrm{Zr}}_{x}{\mathrm{Te}}_{5}$ solid solutions, and on the Te site with Se. Proper doping leads to a decrease in resistivity and an enhancement of thermopower which results in a doubling of the power factor (electronic properties) which is then very competitive with the power factor of existing thermoelectric materials in these temperature regimes.