Self-consistent determination of the band offsets inInAsxP1−x/

Abstract

Low-and room-temperature optical absorption spectra are presented for a series of InAs x P 1Ϫx /InP strainedlayer multiple quantum well structures ͑0.11 рxр0.35͒ 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, 1990͒, Vol. 32, p. 56͔. From these self-consistent fits, both the bowing parameter of bulk unstrained InAs x P 1Ϫx and the band offsets of the heterostructures are deduced self-consistently. The conduction-band offsets thus determined represent 75%Ϯ3% of the total strained band-gap differences at both low ͑liquid He͒ 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 ͑1984͔͒. The values determined for the bowing parameters are found to differ slightly between 0.10Ϯ0.01 eV at low temperature and 0.12Ϯ0.01 eV at room temperature.

Temperature dependence of the band gap in InAsyP1−y

“…[6][7][8] Also reported [8][9][10][11][12][13][14][15][16] is the optoelectronic and material growth, including InAsP/InP strained-quantum wells. For InAs y P 1Ϫy , the band gap and its temperature dependence are essential material parameters in the design and fabrication of devices as well as the determination of epitaxial growth conditions.…”

Strain and optical transitions in InAs quantum dots on (001) GaAs

“…The descriptions of the strain given by [8] and [9] are based on the deformation potential of Pikus and Bir [10]. Such a deformation potential has been applied to spatially distributed strains, e.g.…”

High-quality InAsyP1−y step-graded buffer by molecular-beam epitaxy

“…[1][2][3] InAs y P 1Ϫy alloys are also of interest for compositionally graded buffer applications, where the span of lattice constants between InP and InAs provides the opportunity for generating ''virtual substrates'' on InP to support a wide variety of lattice-mismatched devices based on In x Ga 1Ϫx As, In x Al 1Ϫx As, and InAs y P 1Ϫy . This is currently being explored for thermophotovoltaic ͑TPV͒ devices based on In x Ga 1Ϫx As, where the band gaps required for optimal TPV system conversion efficiencies in the range of 0.5-0.6 eV necessitate In x Ga 1Ϫx As compositions (xϭ0.69-0.81) that generate a significant lattice mismatch with respect to the InP substrate.…”