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In x Ga 1 - x As y Sb 1 - y epilayers with a fixed In content of x = 0.145 were grown on GaSb(100) substrates using liquid-phase epitaxy (LPE). The lattice mismatch between the quaternary epilayers and substrates was analyzed for different As contents (y ) by X-ray ω -2 θ . Epilayers with As content between y = 0.120 and y = 0.124 exhibited a positive lattice mismatch, leading to compressive strain. These samples showed a high crystalline quality and flat surfaces, as confirmed by high-resolution X-ray diffraction (HR-XRD) and atomic force microscopy (AFM). Quaternary alloys with As content between y = 0.133 and y = 0.141 displayed a negative lattice mismatch, resulting in tensile strain. Structural defects in these samples were evidenced by HR-XRD and on AFM micrographs. Raman measurements also revealed that lateral strain has a direct impact on the intensities of the LO-like, phonon–plasmon and disorder-activated longitudinal acoustic modes. For all In x Ga 1 - x As y Sb 1 - y films, photoluminescence (PL) spectra showed a bound exciton (BE) transition, with additional features observed in samples under tensile strain, indicating the involvement of native defect centers and donor–acceptor pairs. This study provides new insights into the effect of lateral strain on the crystalline and surface quality, and optical properties of quaternary alloys, relevant for novel optoelectronic applications. [ABSTRACT FROM AUTHOR]

Antimonide−based p − n junctions are particularly attractive for a wide variety of optoelectronic applications in the near and mid-infrared wavelength range. In this work, novel p −type Si−doped In 0.145 Ga 0.855 As 0.123 Sb 0.877 epitaxial layers were grown on GaSb(100) substrates by Liquid Phase Epitaxy (LPE) technique. The XPS spectra measured on Si−doped In 0.145 Ga 0.855 As 0.123 Sb 0.877 layers indicate that Si atoms behave as acceptors. The analysis of the surface depletion region and its relationship with phonon−plasmon L_ coupling were investigated using Raman spectroscopy, giving an acceptor concentration of N A ∼ 5.8 × 1017 cm−3 for a depletion region thickness of d ∼ 9.4 nm. Low temperature photoluminiscence (PL) spectrum for the Si−doped In 0.145 Ga 0.855 As 0.123 Sb 0.877 layers showed a bound excitonic emission peak associated to neutral Sb acceptors, with an activation energy of ∼ 10 meV and a donor−acceptor transition. It was observed that the Si doping reduces the excitonic emission intensity and increases the donor−acceptor pair recombination intensity. [Display omitted] • Novel p − type In 0.145 Ga 0.855 As 0.123 Sb 0.877 epitaxial layers with Si. • Si-doped quaternary alloy exhibits a higher donor-acceptor emission intensity. • Si Sb substitutions generate a highly effective recombination channel. • Study of hole concentration from the phonon-plasmon coupled L − mode. • Growth of p-type quaternary alloy by Liquid Phase Epitaxy (LPE). [ABSTRACT FROM AUTHOR]