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InAs/GaSb strained layer superlattices have been grown by atmospheric pressure MOVPE and the growth conditions optimised by observing, in real time, the in-situ UV absorption of the alkyls in the growth chamber. The Raman scattering of folded longitudinal acoustic phonons in the superlattices has been used as a probe of the periodicity of the superlattice. Atomic force microscopy has also been used to give information about the final surface morphology and RMS roughness of the superlattices. By combining all three techniques, optimum conditions have been found for the growth of short period InAs/GaSb superlattices. These have been used to sandwich a long period superlattice designed for transport measurements. The use of the short period superlattices eliminated additional conducting layers at each end of the semimetallic superlattice and produced structures where the hole and electron densities are equal. Such structures exhibit a dramatic new quantum transport effect where the Hall resistance goes to zero at high pressures and low temperatures.

InAs GaSb strained layer superlattices (SLSs) have been grown by metalorganic vapour phase epitaxy (MOVPE) at atmospheric pressure. Initially the interfaces of the SLS have been biased towards pairs of GaAs or InSb using three different gas switching sequences. Room temperature Raman optical modes show that growing the interfaces using an ALE (atomic layer epitaxy) like switching sequence gives interfaces of very high quality probably near the optimum, which is a monolayer, Growing with other switching sequences leads to one of the interfaces being non-uniform. By growing samples with alternating (InSb,GaAs or GaAs,InSb) pairs of interfaces it is possible to unambiguously assign this non-uniformity to one of the two possible interfaces for the first time. Furthermore, the influence of the band overlap on interface type has been studied using optimised SLSs in the semimetallic regime.

GaInAsP/InP single quantum well (SQW) structures have been grown using low pressure metalorganic vapour phase epitaxy (MOVPE), with growth interruptions used both before and after the quanternary layer growth. The 4 K photoluminescence (PL) spectra for a 10 A thick well exhibited a peak splitting, with PL linewidths of 16 and 20 meV, representing the narrowest ever reported in MOVPE grown GaInAsP/InP SQWs of this thickness. This peak splitting was attributed to well thickness fluctuations of one monolayer, with extended monolayer terraces at the heterointerfaces, the first report of this phenomenon for GaInAsP/InP heterointerfaces. From the effect of variation of the interruption times on the linewidths and splitting of these PL peaks, we conclude that growth interruption of 20 s is sufficient for surface migration to flatten such an interface.