Ga4C-family crystals, a new generation of star thermoelectric materials, achieved by band degeneracies, valley anisotropy, and strong phonon scattering among others

We uncover a new class of high-performance thermoelectric materials, i.e. , supertetrahedral Ga 4 C-family materials with an ultrahigh thermoelectric figure of merit, produced both by a large power factor and ultralow lattice thermal conductivity.