Defect Engineering Boosted Ultrahigh Thermoelectric Power Conversion Efficiency in Polycrystalline SnSe

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Detail(s)

Original languageEnglish
Pages (from-to)58701–58711
Journal / PublicationACS Applied Materials and Interfaces
Volume13
Issue number49
Online published1 Dec 2021
Publication statusPublished - 15 Dec 2021

Abstract

Two-dimensional (2D)-layered atomic arrangement with ultralow lattice thermal conductivity and ultrahigh figure of merit in single-crystalline SnSe drew significant attention among all thermoelectric materials. However, the processing of polycrystalline SnSe with equivalent thermoelectric performance as single-crystal SnSe will have great technological significance. Herein, we demonstrate a high zT of 2.4 at 800 K through the optimization of intrinsic defects in polycrystalline SnSe via controlled alpha irradiation. Through a detailed theoretical calculation of defect formation energies and lattice dynamic phonon dispersion studies, we demonstrate that the presence of intrinsically charged Sn vacancies can enhance the power factor and distort the lattice thermal conductivity by phonon-defect scattering. Supporting our theoretical calculations, the experimental enhancement in the electrical conductivity leads to a massive power factor of 0.9 mW/mK2 and an ultralow lattice thermal conductivity of 0.22 W/mK through the vacancy-phonon scattering effect on polycrystalline SnSe. The strategy of intrinsic defect engineering of polycrystalline thermoelectric materials can increase the practical implementation of low-cost and high-performance thermoelectric generators.

Research Area(s)

  • alpha irradiation, defect engineering, lattice thermal conductivity, phonon scattering, thermoelectrics

Citation Format(s)

Defect Engineering Boosted Ultrahigh Thermoelectric Power Conversion Efficiency in Polycrystalline SnSe. / Karthikeyan, Vaithinathan; Oo, Saw Lin; Surjadi, James Utama; Li, Xiaocui; Theja, Vaskuri C. S.; Kannan, Venkataramanan; Lau, Siu Chuen; Lu, Yang; Lam, Kwok-Ho; Roy, Vellaisamy A. L.

In: ACS Applied Materials and Interfaces, Vol. 13, No. 49, 15.12.2021, p. 58701–58711.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review