Synergistic optimization of thermoelectric properties in CuNiSnSe composited with CuO nanoparticles

• Published in: Physical chemistry chemical physics : PCCP 2024-10, Vol.26 (42), p.2766-2777
• Main Authors: Mani, J, Radha, S, Kiruthika, J, Lakshmanan, Ajith Kumar, Arivanandhan, M, Anbalagan, G
• Format: Article
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d4cp03061c

Quaternary chalcogenides have gained significant attention in thermoelectric (TE) material research for their high thermoelectric conversion efficiency. The present work investigates the optimisation of the thermoelectric performance of Cu 2 NiSnSe 4 utilising the energy filtering effect through the incorporation of CuO into a host matrix. The impact of varying the weight percentage of CuO on the TE properties of the nanocomposite materials was studied and compared with that of pristine Cu 2 NiSnSe 4 . It was observed that the presence of impurity phases significantly enhances phonon-boundary scattering, leading to a substantial decrease in lattice thermal conductivity, particularly in conjunction with the grain boundaries created by the nanocrystals. For pure samples, the maximum power factor was 1480 μW m −1 K −2 at 673 K. Stronger phonon scattering at the interface boundaries created between the Cu 2 NiSnSe 4 matrix and CuO inclusions resulted in a low thermal conductivity of 1.01 W m −1 K −1 for the 10 wt% composite sample. The Cu 2 NiSnSe 4 /10 wt% CuO composite had a maximum zT of 0.69, which was 1.4 times higher than that of the Cu 2 NiSnSe 4 matrix at 673 K. Additionally, an increase in CuO composition resulted in a uniform increase in the Seebeck coefficient and a simultaneous decrease in thermal conductivity, ultimately contributing to the attainment of the highest figure of merit for these materials. CuO-incorporated Cu 2 NiSnSe 4 matrix successfully enhance phonon scattering at grain boundaries, which reduces thermal conductivity and thereby acheived a high figure of merit ( zT ).