Suppression of bipolar diffusion effect on layered anisotropic PbBi4Te7 thermoelectric material via Se alloying.

The unique layered structure and intrinsically low lattice thermal conductivity of ternary compound PbBi 4 Te 7 have rendered it a promising thermoelectric material. However, the bipolar diffusion effect induced by inherent excitation results in deteriorated Seebeck coefficients and amplified thermal conductivity. In this study, the bipolar diffusion effect of PbBi 4 Te 7 is effectively suppressed through enlarging the bandgap via Se alloying, thereby facilitating its potential application as a complementary counterpart to p-type materials. A maximum ZT value of ∼0.67 is achieved in PbBi 4 (Te 0.7 Se 0.3) 7 at 723 K, signifying an impressive improvement of 121 % compared to pure PbBi 4 Te 7. This study provides a novel insight into enhancing the thermoelectric performance of ternary materials. [ABSTRACT FROM AUTHOR]