Enhancement in Thermoelectric Performance in Ti-doped Yb0.4Co4Sb12 Skutterudites via Carrier Optimization and Phonon Anharmonicity

Akshara Dadhich; Madhuvathani Saminathan; Saravanan Muthiah; Animesh Bhui; Suresh Perumal; M S Ramachandra Rao; Kanikrishnan Sethupathi

doi:10.1021/acsami.3c09768

Enhancement in Thermoelectric Performance in Ti-doped Yb_0.4Co₄Sb₁₂ Skutterudites via Carrier Optimization and Phonon Anharmonicity

ACS Appl Mater Interfaces. 2023 Nov 2. doi: 10.1021/acsami.3c09768. Online ahead of print.

Authors

Akshara Dadhich^{1

2}, Madhuvathani Saminathan³, Saravanan Muthiah⁴, Animesh Bhui⁵, Suresh Perumal⁶, M S Ramachandra Rao^{2

7}, Kanikrishnan Sethupathi^{1

7}

Affiliations

¹ Low Temperature Physics Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India.
² Department of Physics, Nano Functional Materials Technology Center and Materials Science Research Center, Indian Institute of Technology Madras, Chennai 600036, India.
³ Laboratory for Energy and Advanced Devices (LEAD), Department of Physics and Nanotechnology, SRM Institute of Science and Technology, Kattankulathur, Chengalpattu 603203, India.
⁴ Advanced Materials and Device Metrology Division, National Physical Laboratory, New Delhi 110012, India.
⁵ New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, Karnataka 560 064, India.
⁶ Laboratory for Energy and Advanced Devices (LEAD), Department of Materials Science and Metallurgical Engineering, Indian Institute of Technology, Hyderabad, Telangana 502 285, India.
⁷ Quantum Centre of Excellence for Diamond and Emergent Materials (QuCenDiEM), Indian Institute of Technology Madras, Chennai 600036, India.

PMID: 37916737
DOI: 10.1021/acsami.3c09768

Abstract

Yb_0.4Co₄Sb₁₂, being a well-studied system, has shown notably high thermoelectric performance due to the Yb filler atom-driven large concentration of charge carriers and lower value of thermal conductivity. In this work, the thermoelectric performance of Yb_zCo_4-xTi_xSb₁₂ (where z = 0, x = 0 and z = 0.4, x = 0, 0.04, and 0.08) upon Ti doping prepared by the melt-quenched-annealing followed by spark plasma sintering (SPS) has been studied in the temperature range of 300-700 K. Addition of Yb and doping of donor Ti at the Co site simultaneously increase the electrical conductivity to 1453.5 S/cm at 300 K, which ultimately boosts the power factor as high as ∼4.3 mW/(m·K²) at 675 K in Yb_0.4Co_3.96Ti_0.04Sb₁₂. Adversely, a significant reduction in thermal conductivity is obtained from ∼7.69 W/(m·K) (Co₄Sb₁₂) to ∼3.50 W/(m·K) (Yb_0.4Co_3.96Ti_0.04Sb₁₂) at ∼300 K. As a result, the maximum zT is achieved as ∼0.85 at 623 K with high hardness of 584 H_V for the composition of Yb_0.4Co_3.96Ti_0.04Sb₁₂, which demonstrates it to be an efficient material suitable for intermediate temperature thermoelectric applications.

Keywords: Co4Sb12 skutterudites; Ti doping; Yb filling; high zT; large power factor.