Both $n$-type and $p$-type conductivity can be obtained in cadmium telluride. The intrinsic band gap of cadmium telluride is 1.45 ev. Electron and hole mobilities are at least 30 ${\mathrm{cm}}^{2}$/volt sec. The activation energies of $p$-type impurities are much larger than those of $n$-type impurities in cadmium telluride, indicating an explanation for the failure to find $p$-type conductivity in cadmium sulfide or selenide.