Efficacy of pyrostilpnite (Ag3SbS3) mineral as thermoelectric material: A first principles study

Recently, environmental-friendly chalcogenides composed of cost-effective elements began contributing its proportion to the thermoelectric (TE) industry attributed to its greater conversion efficiency. On the track of exploration, suitability of pyrostilpnite (Ag3SbS3), a naturally available semiconducting mineral is investigated for TE applications using density functional and Boltzmann transport theory. The electronic band structure unveils its indirect band gap of 1.54 eV with favourable band feature (i.e.): degenerate flat bands resulting constructive carrier effective masses. Likewise, the reasonable Seebeck coefficient as well as electrical conductivity yields noticeable power factor of 1.611 mW m-1 K-2 at optimum electron concentration. Besides, the calculated lattice thermal conductivity reaches 0.392 W m-1 K-1 at 900 K. The synergetic effect of PF and kL intensely elevated the figure of merit to 1.64 at 900 K. The current study manifests eco-friendly pyrostilpnite mineral as a potentially beneficial candidate for TE devices and it could act as the waymark for experimental investigations.