Optical characterization of highly mismatched InP/GaAs(l11)B epitaxial heterostructures

In this work, we investigate heteroepitaxial layers of InP with various thicknesses grown by metalorganic chemical vapor deposition on (111)B surfaces of GaAs substrates. We evaluate the heteroepilayers using low temperature photoluminescence (PL) and we discuss the dependence of the PL spectrum on temperature for the thick epilayer. We determine the residual strain for the various layer thicknesses with photoluminescence excitation spectroscopy. The strain is due to different lattice constants of layer and substrate material and is relaxed by the nucleation of misfit dislocations during growth. This relaxation process depends on substrate orientation, layer thickness and growth conditions.