Molecular beam epitaxial growth of lattice-mismatched In0.77Ga0.23As on InP

It is demonstrated that lattice-mismatched InxGa1−xAs (x = 0.77) can be grown by molecular beam epitaxy on InP substrates with mobilities and photoluminescence (PL) intensities comparable to those of the lattice-matched InxGa1−xAs (x = 0.53). This was accomplished using a graded buffer layer and superlattice dislocation barrier between the substrate and the In0.77Ga0.23As layer. The lattice-mismatched layers have Hall mobilities of 7000–8000 cm2/V sec at room temperature and photoluminescence intensities at liquid nitrogen temperature of 1/2–1/3 of that from the lattice-matched InxGa1−xAs. We also found that the conventional AB etch is not a reliable guide to the electrical and optical qualities of InGaAs layers.