Sb enhancement of lateral superlattice formation in GaInP

Epitaxial layers of GaInP were grown by organometallic vapor phase epitaxy with small amounts of TESb added to control the surface bonding. Above a concentration of Sb/III(v)=0.016, 12 K photoluminescence measurements show that the band gap is reduced, as compared to completely disordered GaInP, by Sb addition and that polarization along the [1¯10] direction is as much as 41 times larger than along [110]. Transmission electron microscopy results show a lamellar domain structure in the [1¯10]-zone axis dark-field images with a period of 120 nm. Atomic force microscopy shows surface undulations with the same period along the [1¯10] direction. The results demonstrate an increase in the magnitude of the presence of lateral composition modulation with increasing Sb concentration.