Facile composite engineering to boost thermoelectric power conversion in ZnSb device

作者：Theja, Vaskuri C. S.; Karthikeyan, Vaithinathan; Nayak, Sanjib; Kandira, Kadir Ufuk; Assi, Dani S.; Kannan, Venkataramanan; Roy, Vellaisamy A. L.^*

来源：Journal of Physics and Chemistry of Solids, 2023, 178: 111329.

DOI：10.1016/j.jpcs.2023.111329

• ZnSb
• Nano-inclusion
• Phonon scattering
• Thermal conductivity

Zinc antimonide (ZnSb) is one of the alternatives for commercial thermoelectric materials due to its non-toxic, low-cost, and earth-abundant nature. However, its simple crystal structure causes strong phonon vibrations, which enhance lattice thermal conductivity. In this work, we systematically studied the effect of gamma-Al2O3 nano-inclusions on ZnSb. Our results show that composite engineering imparts lattice phonon scattering for reduced thermal conductivity and low-energy carrier filtering for enhanced Seebeck coefficient. The obtained figure of merit in the ZnSb+5% gamma-Al2O3 sample at 673 K is nearly two-fold higher than the pristine sample. Our fabricated 2-leg ZnSb+5% gamma-Al2O3 device displayed a power generation of 0.11 mu W at Delta T of 200 degrees C. Furthermore, adding gamma-Al2O3 nano-inclusions improve the mechanical and thermal stabilities due to grain boundary hardening and dispersion strengthening. Overall, the addition of gamma-Al2O3 nano-inclusions to ZnSb enhancing the Seebeck co-efficient, reducing thethermal conductivity, and improving mechanical and thermal stability significantly.