Formation of Tetragonal InBi Clusters in InAsBi/InAs(100) Heterostructures Grown by Molecular Beam Epitaxy

Abstract

This work analyses the Bi incorporation in InAs1?xBix/InAs(100) epilayers grown by MBE through advanced transmission electron microscopy techniques. Samples grown from 350–400 ?C resulted in Bi contents <3:3% exhibiting compositional variation in the growth direction. In contrast, roughly spherical clusters appeared in the sample grown at lower temperatures. The clusters are made up of the binary InBi with a tetragonal PbO phase surrounded by a matrix of InAs0:95Bi0:05 indicating the Bi solubility limit in InAs. These InBi crystals underwent a cubic distortion and are tilted 55? with regard to the InAsBi matrix. The crystallographic relationships are analysed in detail.