Abstract
? 2022 Elsevier B.V.InSb has superior electronic transport with low bandgap and high mobility of charge carriers, however, its high lattice thermal conductivity makes it less applicable for thermoelectric applications. Herein we report an effective approach to simultaneously enhance the power factor and reduce total thermal conductivity by isoelectronic doping of Bi for Sb. A series of polycrystalline InSb1-xBix is prepared. The enhanced power factor is attributed to the increase of carrier concentration by charge transfer from the Bi d-orbital states to the In 4d-orbital states based on analyses of both the Bi and In L3-edge XANES spectra of InSb1?xBix. The reduced total thermal conductivity arises from the reduced lattice thermal conductivity due to the point defects. The strain field fluctuations are evidenced by the blue shift in Raman spectra of InSb1-xBix. As a result, zT = 0.56 is attained at 700 K, which is 16% higher than the pristine InSb.
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