Nonexistence of Long-Range Order in Ga0.5In0.5P Epitaxial Layers Grown on (111)B and (110)GaAs Substrates

It has been found that Ga 0.5 In 0.5 P layers grown at 700°C on (111)B and (110)GaAs substrates do not show {1/2, 1/2, 1/2} superlattice (SL) formation, in contrast to that for the layers grown on (001)GaAs. The band-gap energy for these layers, which show no SL and are lattice-matched to GaAs, was estimated to be 1.918±0.002 eV at room temperature.