FeP precipitates in hydride-vapor phase epitaxially grown InP:Fe

Abstract

Fe-doped InP was grown by hydride-vapor phase epitaxy. Doping levels up to 8×1018 cm−3 were determined by secondary ion mass spectrometry. Additionally performed photoluminescence measurements revealed a homogeneous distribution of electrically active Fe atoms. From microstructural investigations by analytical transmission electron microscopy, spherical-shaped precipitates were detected in plan-view samples. These precipitates with diameters up to 13 nm are homogeneously arranged in the epilayer. For conglomerates of precipitates a distinct enrichment with Fe and P was measured by a comparative energy dispersive x-ray analysis. The lattice plane distances of the precipitates were deduced from the electron diffraction patterns and from high-resolution electron micrographs. A comparison with calculated values for different Fe–P alloys indicates that the precipitates consist mainly of orthorhombic FeP.