IV–VI compounds on fluoride/silicon heterostructures and IR devices

Abstract

We present recent results on the growth of IV–VI lead-chalcogenide narrow gap semiconductors on silicon and subsequent IR device fabrication. Heteroepitaxy is achieved using intermediate stacked approximately 2000 Å thick epitaxial CaF2BaF2 buffer layers which allow us to overcome the large lattice mismatch (up to 20%) and, even more important, thermal expansion mismatch between lead chalcogenides and silicon. By growing different lead chalcogenides such as PbS, Pb1−xEuxSe, PbTe and Pb1−xSnxSe we have fabricated sensor arrays with cut-off wavelengths covering the whole thermal IR range from 3 microm up to above 12 microm.