Electronic structure and thermoelectric performance of Zintl compound Sr_3GaSb_3: A first-principles study

摘要

By using first-principles method and Boltzmann theory, we simulated the thermoelectric transport properties of p-type and n-type Sr_3GaSb_3. It is found that the thermoelectric figure-of merit (ZT) of n-type Sr_3GaSb_3 is probably better than that of p-type, mainly due to its large band degeneracy. Moreover, a high ZT value of 1.74 at 850 K can be achieved for p-type Sr_3GaSb_3, along the redirection, corresponding to the carrier concentration 3.5×10~(20)e cm~(-3) We propose that the high ZT value of experimentally synthesized p-type Sr_3GaSb_3 is originated from appearing of the larger number of band valley on the top of valence bands.