Self-consistent determination of the band offsets in $\mathrm{In}{\mathrm{As}}_x{\mathrm{P}}_{1-x}/\mathrm{InP}$ strained-layer quantum wells and the bowing parameter of bulk $\mathrm{In}{\mathrm{As}}_x{\mathrm{P}}_{1-x}$

Low- and room-temperature optical absorption spectra are presented for a series of $\mathrm{In}{\mathrm{As}}_x{\mathrm{P}}_{1-x}/\mathrm{InP}$ strainedlayer multiple quantum well structures ($0.11<~x<~0.35$) grown by low-pressure metal-organic vapor phase epitaxy using trimethylindium, tertiarybutylarsine, and phosphine as precursors. The well widths and compositions in these structures are exactly determined from the use of both high-resolution x-ray diffraction and transmission electron microscopy on the same samples. The absorption spectra are then analyzed by selfconsistently fitting, for the five samples, the excitonic peak energy positions with transition energies determined from a solution to the Schrödinger equation in the envelope function formalism using the well-known Bastard/Marzin model [J. Y. Marzin et al., in Semiconductors and Semimetals, edited by Thomas P. Pearsall, (Academic, New York, 1990), Vol. 32, p. 56]. From these self-consistent fits, both the bowing parameter of bulk unstrained $\mathrm{In}{\mathrm{As}}_x{\mathrm{P}}_{1-x}$ and the band offsets of the heterostructures are deduced self-consistently. The conduction-band offsets thus determined represent 75%±3% of the total strained band-gap differences at both low (liquid He) and room temperatures. These values of the band offsets are consistent with the predictions of the quantum dipole model [J. Tersoff, Phys. Rev. B 30, 4874 (1984)]. The values determined for the bowing parameters are found to differ slightly between 0.10±0.01 eV at low temperature and 0.12±0.01 eV at room temperature.