Low-pressure organometallic vapor phase epitaxy of coherent InGaAsP/InP and InGaAsP/InAsP multilayers on InP(001)

InGaAsP/InP and InGaAsP/InAsP multilayers were grown on InP(001) by low-pressure organometallic vapor phase epitaxy. Large growth rates of ≈0.4–0.6 nm $s−1$ and an increased element-V overpressure were used to limit the morphological evolution of the strained layers during growth and to compensate for the relatively high temperatures (≈630 °C) necessary for vapor phase epitaxy in a diffusion-limited regime. High-resolution x-ray diffraction and reciprocal lattice mapping analyses indicate fully strained multilayers of high crystalline quality. This structural information, combined with room-temperature photoluminescence (PL) measurements, allows us to determine accurately the thickness and the composition of the layers. Well-resolved excitonic transitions between the heavy- and light-hole valence bands and the conduction band are visible in the low-temperature optical absorption spectra for compressive InGaAsP/InP multilayers. The PL spectra for compressive InGaAsP/InP structures show sharp and intense transitions between the first confined levels in the conduction and the heavy-hole bands. The PL peaks for InGaAsP/InAsP heterostructures are slightly broader than for InGaAsP/InP multilayers due to the more complex (quaternary-ternary) interface but remain sharp and intense.