Journal Article

Improved Thermoelectric Properties of Se-Doped n-Type PbTe^sub 1-x^Se^sub x^ (0 <= x <= 1)

Bhatt, Ranu, Gupta, S K, Basu, Ranita, Aswal, D K, Bhattacharya, S, Singh, Ajay

2013

Overview

Issue Title: 2012 International Conference on Thermoelectrics. Guest Editors: Ryoji Funahashi, Donald Morelli, Lasse Rosendahl, and Jihui Yang Enhancement of the thermoelectric figure of merit is of prime importance for any thermoelectric material. Lead telluride has received attention as a potential thermoelectric material. In this work, the effect of Se substitution has been systematically investigated in PbTe^sub 1-x^Se^sub x^. The thermoelectric properties of synthesized alloys were measured in the temperature range of 300 K to 873 K. For the particular composition of x = 0.5, [alpha] was highest at ~292 [mu]V/K, while k was lowest at ~0.75 W/m-K, resulting in the highest dimensionless figure of merit of ZT [asymptotically =] 0.95 at 600 K. The increase in thermopower for x = 0.5 can be attributed to the high distortion in the crystal lattice which leads to the formation of defect states. These defect states scatter the majority charge carriers, leading to high thermopower and high electrical resistivity. The dramatic reduction of the thermal conductivity for x = 0.5 can be attributed to phonon scattering by defect states.[PUBLICATION ABSTRACT]

• Publisher: Springer Nature B.V
• Subject: Defects / Electric power / Heat conductivity / Semiconductor doping / Thermal energy