Multistage pore structure in Bi2Te3/SiC composites: achieving lower thermal conductivity and enhanced thermoelectric Performance†

This study presents a novel approach to enhancing thermoelectric performance by developing Bi₂Te₃/SiC composites with a multistage pore structure aimed at reducing thermal conductivity. The composites were synthesized using a combination of hydroxylation, silane functionalization, and CTAB surface modification to ensure improved interfacial interactions and a well-dispersed composite structure. The introduction of a multistage pore network resulted in enhanced phonon scattering, leading to a significant reduction in thermal conductivity to 0.19 W m⁻¹ K⁻¹. Consequently, the figure of merit (ZT) reached a remarkable value of 0.53 at 300 K, showcasing the effectiveness of multistage pore engineering in balancing phonon suppression and electrical transport. These findings indicate that the multistage pore structures and surface-functionalization techniques are an effective strategy for enhancing thermoelectric materials by optimizing phonon scattering and charge transport.