Paper published in Journal of Applied Physics – “Enhanced room temperature electronic and thermoelectric properties of the dilute bismuthide InGaBiAs”

In collaboration with Prof. Joshua Zide’s group at University of Delaware, our paper “Enhanced room temperature electronic and thermoelectric properties of the dilute bismuthide InGaBiAs” was recently published in Journal of Applied Physics (J. Appl. Phys. 112, 093710 (2012)).  In this work, the ExSiTE lab measured the thermal conductivity of Si doped InGaBiAs films with varying Bi concentration to support the electrical resistivity and Seebeck coefficients measurements conducted at the University of Delaware.  We found that the bismuth scattering suppressed the thermal conductivity of these bismuthides, that, along with enhanced electrical conductivity and carrier concentrations, could make these bismuthides an exceptional thermoelectric material.

Abstract

We report room temperature electronic and thermoelectric properties of Si-doped In0.52Ga0.48 BiyAs1-y with varying Bi concentrations. These films were grown epitaxially on a semi-insulating InP substrate by molecular beam epitaxy. We show that low Bi concentrations are optimal in improving the conductivity, Seebeck coefficient, and thermoelectric power factor, possibly due to the surfactant effects of bismuth. We observed a reduction in thermal conductivity with increasing Bi concentration, which is expected because of alloy scattering. We report a peak ZT of 0.23 at 300 K.