Influence of surface strain on the MOVPE growth of InGaP epitaxial layers

In this paper, we present a study of the influence of strain on the composition uniformity, phase separation and ordering of compressive and tensile strained InGaP epitaxial layers grown on GaP and GaAs substrates. The paper demonstrates how strain, caused by lattice mismatch, influences the spinodal-like decomposition and ordering in InGaP layers. We concentrated our efforts on an alloy with the lattice mismatch close to a value of Delta a/a = 10(-2). Transmission electron microscopy (TEM), low temperature photoluminescence and atomic force microscopy (AFM) were used to demonstrate that epitaxial layers grown under compressive strain have additional properties in comparison to those ones grown under tensile strain. The presence of ordering, spinodal-like decomposition and compositional fluctuations was studied in relation to the sign of strain.