High Thermoelectric Performance in AgBiSe-Incorporated n-Type BiTeSeCl.

Bismuth telluride-based (BiTe) alloys have long been considered the best thermoelectric (TE) materials at room temperature. However, the n-type BiTe alloys always exhibit poor thermoelectric performance than their p-type counterpart, which severely limits the energy conversion efficiency of thermoelectric devices. Here, we demonstrate that incorporating AgBiSe can concurrently regulate the electrical and thermal transport properties as well as improve the mechanical performance of n-type BiTeSeCl for high thermoelectric performance. Among these, AgBiSe effectively enhanced the Seebeck coefficients of n-type BiTeSeCl due to the reduced carrier concentration and reduced the thermal conductivity of n-type BiTeSeCl owing to the enhanced phonon scattering by AgBiSe as well as its low thermal conductivity nature. Consequently, the simultaneous optimization of electrical and thermal transport properties enables us to achieve a maximum of ∼1.21 (at ∼353 K) and an average of ∼1.07 (300-433 K) for 3.5 wt % AgBiSe-incorporated BiTeSeCl, which are ∼25.62 and ∼23.36% larger than those of BiTeSeCl, respectively. This work proves that the incorporation of AgBiSe is an efficient way to improve the thermoelectric performance of bismuth telluride-based materials.