INFLUENCE OF MISMATCH OF THE LATTICE-PARAMETERS ON THE STRUCTURAL, OPTICAL, AND TRANSPORT-PROPERTIES OF INGAAS LAYERS GROWN BY MOLECULAR-BEAM EPITAXY ON INP(100) SUBSTRATES

The influence of mismatch stress on the structural, optical, and trans port properties of thick InGaAs layers grown on InP(100) substrates by molecular-beam epitaxy is investigated. It is found that layers havin g tensile stress can be grown with a greater mismatch than compressive ly stressed layers before plastic relaxation sets in. The critical mis match for thick InGaAs layers is not described with sufficient accurac y by either the mechanical equilibrium model or the energy balance mod el. The range of mismatches required to obtain high carrier mobilities and high radiative recombination efficiencies in InGaAs layers grown on InP substrates is much narrower than the pseudomorphic growth range . The maximum mobilities and minimum widths of the photoluminescence p eak are attained in layers matched with the substrate in terms of the lattice parameter and also in slightly gallium-enriched layers. The co mpositional dependence of the width of the band gap is investigated wi th allowance for the influence of stress. (C) 1997 American Institute of Physics.