Thermoelectric properties of Mg2Si coatings deposited by pack cementation assisted process on heavily doped Si substrates

Abstract

This work presents a study of structural and thermoelectric properties of Mg2Si coatings deposited on heavily doped p- and n-type Si substrates, at 650 C. The as-grown layers were smooth and uniform in thickness without any texture, voids, or large density of cracks. The sign of Seebeck coefficient in deposited layers follows the one of the corresponding substrate, indicating effective doping of the grown layers with the dopant already present in Si substrate (B for p-type and As for n-type). Doping levels of ∼9 × 1018 cm-3 for p-type and ∼5 × 10 18 cm-3 for n-type, were obtained. IR reflectivity analysis revealed a strong mode at 272 cm-1 and a shoulder at 316 cm-1. Thermoelectric properties were successfully modeled by a multiple-band model, with optical phonon scattering. Temperature dependence of electrical conductivity for the deposition layers. The lines represent the theoretical fitting. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.