Enhancement in thermoelectric performance of SiGe nanoalloys dispersed with SiC nanoparticles. Issue 36 (8th September 2017)

• Record Type: Journal Article
• Authors: Bathula, Sivaiah; Jayasimhadri, M.; Gahtori, Bhasker; Kumar, Anil; Srivastava, A. K.; Dhar, Ajay
• Is Part Of: Physical chemistry chemical physics. Volume 19:Issue 36(2017)
• Page Start: 25180
• Page End: 25185
• Publication Date: 2017-09-08
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c7cp04240j
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : The enhancement of thermoelectric figure-of-merit with SiC dispersion in SiGe nanostructured alloy. Abstract : SiGe is one of the most widely used thermoelectric materials for radioisotope thermoelectric generator applications for harnessing waste-heat at high temperatures. In the present study, we report a simple experimental strategy for enhancing the thermoelectric and mechanical properties of n-type SiGe nanoalloys by dispersing SiC nanoparticles in a SiGe nanoalloy matrix. This strategy yielded a high value of figure-of-merit ( ZT ) of ∼1.7 at 900 °C in the SiGe/SiC nanocomposite, which is nearly twice that reported for its pristine bulk counterpart and ∼15% higher than that of pristine SiGe nanoalloys. This significant enhancement in the ZT primarily originates from a reduction in the lattice thermal conductivity, owing to a high density of nano-scale interfaces, lattice-scale modulations and mass fluctuations, which lead to extensive scattering of heat-carrying phonons. The dispersion of SiC nanoparticles also significantly enhances the mechanical properties of the resulting SiGe/SiC nanocomposite, including fracture toughness and hardness. The enhancement in the thermoelectric and mechanical properties of the SiGe/SiC nanocomposites has been correlated with their microstructural features, elucidated employing X-ray diffraction, and scanning and transmission electron microscopy.