Electronic structure and thermoelectric performance of Zintl compound Sr3GaSb3: A first-principles study

By using first-principles method and Boltzmann theory, we simulated the thermoelectric transport properties of p-type and n-type Sr3GaSb3. It is found that the thermoelectric figure-of merit (ZT) of n-type Sr3GaSb3 is probably better than that of p-type, mainly due to its large band degeneracy. Moreover, a high ZT value of 1.74 at 850K can be achieved for n-type Sr3GaSb3 along the yy direction, corresponding to the carrier concentration 3.5 x 10(20) e cm(-3). We propose that the high ZT value of experimentally synthesized p-type Sr3GaSb3 is originated from appearing of the larger number of band valley on the top of valence bands. (C) 2014 AIP Publishing LLC.