Angle-resolved photoemission study of the high-performance low-temperature thermoelectric materialCsBi4Te6

We report a study of the valence-band electronic structure of the newly discovered thermoelectric material, ${\mathrm{CsBi}}_4{\mathrm{Te}}_6,$ using angle-resolved photoelectron spectroscopy. This material exhibits quasi-one-dimensional behavior, which is related to its unique crystal structure. The highly anisotropic band dispersions might explain the large value of the figure of merit, $ZT,$ observed in the hole-doped systems. Our experimental results are compared with a recent theoretical band-structure calculation.