Thermoelectric properties of p-type MnSe

Abstract

Semiconducting manganese selenide (MnSe), crystalizing in a cubic structure with a wide band gap, is focused on in this work for its potential as an ecofriendly thermoelectric material. Pristine MnSe exhibits a low carrier concentration of ∼1.3 × 1017 cm−3 at room temperature, which can be dramatically increased to ∼2.6 × 1021 cm−3 primarily resulting from the Mn-vacancy introduced by Na-doping at Mn site. The broad range of carrier concentration not only enables a reliable prediction of the electrical transport properties using a single parabolic band (SPB) model with the acoustic scattering, but also provides a well understanding of its underlying material physics. Such a doping and the simultaneously induced Mn-vacancies provide additional phonon scattering, leading to a reduced lattice thermal conductivity of ∼1.2 W/m-K at high temperatures.