Structural and optical studies on molecular beam epitaxially grown (InAs) m(AlAs) m and (InAs) m(GaAs) m short-period strained layer superlattices

Abstract

Binary consisting (InAs) m (AlAs) m and (InAs) m (GaAs) m short-period strained layer superlattice InP substrates were grown and their structural and optical properties were examined. Mirror-like surface morphologies were obtained as long as their total thicknesses were less than a critical value. X-ray diffraction measurements showed the formation of atomically ordered periodic superstructure. Photoluminescence spectra measured at 77 K revealed good cry stalline quality in spite of about 7% lattice mismatch between the binary layers. The peak energy changes greatly on (InAs) m (IlAs) m according to the layer thickness, while it varies by a small amount on (InAs) m (GaAs) m structures, which reflects to the layer band gap discontinuities between InAs and AlAs. These structures can be substituted for InAlAs and InGaAs alloys.