Enhanced thermoelectric performance of n-type PbTe through the introduction of low-dimensional C60 nanodots.

Lead telluride (PbTe) has long been considered as an ideal p -type thermoelectric material at an intermediate temperature range. However, the relatively low thermoelectric performance of n -type PbTe largely limits the commercial applications of integral PbTe devices. In current work, we report that a significant enhancement of the ZT value of ≈1.3 can be achieved at 823 K in PbTe 0.998 I 0.002 -0.5%C 60 by adding low-dimensional C 60 nanodots. This remarkable improvement in thermoelectric performance is attributed to the incorporation of C 60 in n -type PbTe matrix, which creates dense nanodots that can simultaneously manipulate electron and phonon transport. On one hand, the dispersion of C 60 nanodots in n -type PbTe matrix leads to highly depressed lattice thermal conductivity (κ lat) (∼52%) due to the refinement of grains and the extra phonon scattering centers. On the other hand, the introduction of C 60 nanodots increases the scattering parameter r x , and brings about the overall improvement of Seebeck coefficient S , especially at room temperature. This work demonstrates the great potential of low-dimensional dopant in optimizing PbTe thermoelectric materials, which should be equally applicable in improving the performance of other thermoelectric materials. • C 60 nanodots can simultaneously manipulate electron and phonon transport. • C 60 nanodots refines the grains to decrease the κ lat. • C 60 nanodots triggers additional scattering mechanisms to further reduce the κ lat. • The introduction of C 60 nanodots enhances the S by increasing the r x. • The C 60 -contained sample has a 45% enhancement in ZT maximum. [ABSTRACT FROM AUTHOR]