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In 0.145 Ga 0.855 As y Sb 1− y semiconductor alloys were grown on GaSb(100) substrates by varying the As content by liquid phase epitaxy (LPE). We demonstrated that the growth mechanism of these quaternary alloys is mainly constituted by two stable bonding configurations, Ga−Sb and In−As. These quaternary alloys showed a high crystalline quality due to the nearly lattice-matched epitaxial growth to the GaSb substrate. We identified a tensile strain of the In 0.145 Ga 0.855 As y Sb 1− y alloys on the GaSb substrate, strain that increases with the As content. In the bulk region of these crystalline alloys it was noticed a greater fonon-plasmon coupling than in the surface space-charge region. In addition, we found that the band gap energy of the In 0.145 Ga 0.855 As y Sb 1− y alloys can be easily engineered in the near infrared by varying the As content. Excitonic transitions were observed in these quaternary alloys, whose energy decreases with the As content. We employed a theoretical method that considers spin-orbit coupling for the determination of the band gap energy, which is in agreement with experimental results. These findings provide an important understanding of the growth dynamics, and of the optical and structural properties of the In 0.145 Ga 0.855 As y Sb 1− y crystalline alloys by varying the As content for near infrared applications using the band gap engineering. Image 1 • I n 0.145 G a 0.855 A s y S b 1 − y alloys were grown on GaSb substrate by varying the As content. • The quaternary alloys were grown by Liquid Phase Epitaxy (LPE). • The growth mechanism of these alloys is mainly constituted by G a − S b and I n − A s. • The excitonic transition energies of the alloys decrease with the A s content. [ABSTRACT FROM AUTHOR]

We investigated p- and n-type In 0.145 Ga 0.855 As 0.108 Sb 0.892 semiconductor alloys grown on GaSb (100) substrates by the liquid phase epitaxy (LPE) technique with different Zinc (Zn) and Tellerium (Te) mole fractions, respectively. Photoluminescence (PL) spectra showed a band gap narrowing effect for p-type doping and a band gap widening for n-type doping, attributed to the type of carrier concentration. The carrier concentration was determined from the band-to-band transition of the PL spectra in the range of 1.20 × 1016 to 2.80 × 1017 and 7.75 × 1016 to 1.02 × 1018 cm−3 for electrons and holes, respectively. Raman spectroscopy measurements showed the phonon modes LO (GaSb–InAs)-like and TO (GaSb–InAs)-like for both types of doping. The frequency dispersion of these modes is closely tied to the presence of native defects, such as vacancies of Ga(V Ga), antisites of Ga in Sb (Ga Sb), and V Ga –Ga Sb complexes. Incorporation of Zn- and Te-doping into the lattice led to a notable reduction in the full width at half maximum (FWHM) of the LO (GaSb–InAs)-like mode, as these dopants effectively diminished native defects. A detailed model is presented for the incorporation of dopants and their effect on the crystal quality. Phonon–plasmon coupling was observed through the L − mode, which overlaps with the TO (GaSb–InAs)-like mode for the carrier concentrations observed in the doped alloys. A theoretical estimation of the frequencies of the coupled modes L + and L − was implemented as a function of the carrier concentration, based on the effective dielectric function of the quaternary compound. The L + coupled mode shifts from the phononic to the plasmonic domain for theoretical electron concentrations ranging from ∼ 1017 to 5 × 1018 cm−3, while in p-type conductivity, the L + mode remains in the phononic domain for the same range of hole concentrations. The increase in the frequency of the L + mode with carrier concentration, such as the plasma frequency, provides another reliable method for determining carrier concentrations. This study reveals the physical mechanism of Zn an Te incorporation into InGaAsSb, which is required for the integration of p- and n-type doped quaternary alloys into optoelectronic applications. In addition, it provides a comprehensive understanding of the complex interaction mechanisms, including LO phonon–plasmon coupling modes and optical transitions, opening up new lines for exploring the electrical and structural properties of these materials. [Display omitted] • The Zinc doping process reduces native Ga vacancies in InGaAsSb alloys. • Te dopant incorporates into Sb sites, decreasing the number of Ga antisites in Sb. • P-type Zn dopants induce a band gap narrowing of InGaAsSb alloys. • N-type Te dopants generate a carrier-dependent band gap widening. • Phonon–plasmon coupling transitions from phononic to plasmonic regimen. [ABSTRACT FROM AUTHOR]