Ordering in GaxIn1−xAsyP1−y grown on GaAs by metalorganic vapour-phase epitaxy

Abstract We have investigated ordering behaviour in MOVPE-grown GaInAsP lattice-matched to GaAs using luminescence and diffraction methods. Our observations indicate that the occurrence of ordering variants depends not only on the growth conditions and the layer composition but is also extremely sensitive to very small substrate misorientation from (0 0 1). For GaInAsP alloys with low arsenic content ( y ∼0.15) the ordering behaviour is very similar to that in the well-studied (In,Ga)P system. Polarization dependent PL reveals that in comparison to InGaP, the degree of ordering in the quaternary gets weaker with rising arsenic content. For higher arsenic content ( y ⩾0.5) weak ordering is detected only for layers with y ≈0.7 when grown with a high V/III ratio in the gas phase. The observed valence-band splittings were ≈12 meV for y =0.15 and 8 meV for y =0.7, respectively.