Semimetallic properties of SnTe/PbSe type-II superlattices

We prepared the SnTe/PbSe superlattices, and measured electrical and optical properties at room temperature. The superlattice showed semimetallic properties resulting from type-II band offset between SnTe and PbSe. Though nondope SnTe had hole concentration around 3×1020 cm−3, nondope SnTe/PbSe superlattices with thin SnTe layers showed n-type conduction with carrier concentrations less than 2×1018 cm−3 and carrier mobility comparable or higher than that of PbSe, keeping semimetallic properties in the optical transmission spectra. These properties are discussed with the band offset of SnTe/PbSe heterojunction.