Interface manipulation in GaxIn1-xAs/InP multiple-layer structures grown by chemical beam epitaxy

In this study the control of interfacial layers in nanometre thin GaxIn1-xAs/InP heterostructures is demonstrated by variation of the growth interruption sequence (GIS) at the binary-ternary interfaces. All samples have been prepared by chemical beam epitaxy simultaneously growing the structures on exact (100) substrates and (100) substrates misoriented by 2 degrees towards (110). Characterization was by means of photoluminescence (PL) spectroscopy and high-resolution x-ray diffraction. It is shown that both composition and thickness of the interfacial layers can be manipulated on the (sub)monolayer scale with GIS times of the order of seconds. According to analysis of the x-ray data, interfaces can be tuned from +4 x 10(-3) compression to -4 x 10(-3) tension around nominally lattice-matched GaxIn1-xAs quantum wells of six monolayers thick. The PL investigations show that the tensile GaxIn1-xP interfaces have no effect on the position of the PL peak maximum whereas compressive, InAs-like interfaces shift the transition to lower energy. This trend can be qualitatively understood but for all samples the calculated transition energies are higher than the measured values. Recommendations are given for further work which is not only of importance to the InP/GaxIn1-xAs system but should be applicable to quantum well structures in other materials where heterojunctions involve changes in both the group V and group III sublattices.