Effect of oxygen incorporation on the vibrational properties of Al0.2Ga0.3In0.5P:Be films

• Published in: Thin solid films 2011-10, Vol.520 (1), p.53-56
• Main Authors: SOUBERVIELLE-MONTALVO, C, VITAL-OCHOA, O, DE ANDA, F, VAZQUEZ-CORTES, D, RODRIGUEZ, A. G, MELENDEZ-LIRA, M, MENDEZ-GARCIA, V. H
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Crystal structure; Deterioration; Disorders; Exact sciences and technology; Gallium arsenide; Inclusions; Lattices; Materials science; Mechanical and acoustical properties; Methods of deposition of films and coatings; film growth and epitaxy; Molecular, atomic, ion, and chemical beam epitaxy; Optical properties; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Other semiconductors; Phonons; Physical properties of thin films, nonelectronic; Physics; Specific materials; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2011.06.033

The vibrational properties of Al0.2Ga0.3In0.5P:Be films grown on (100) GaAs substrates by solid source molecular beam epitaxy varying the phosphorous cracking-zone temperature (PCT) were studied by Raman spectroscopy. The Raman-intensity ratio between the allowed longitudinal optical and the forbidden transverse optical (TO) phonons, and the full width at half maximum of their Lorentzian fits were used to characterize the crystalline quality of the films. The Raman spectra from the samples show changes in the shape and intensity of phonon resonances depending on the PCT variation, indicating that the disorder in the lattice increases with PCT. The increasing disorder is related to the inclusion of oxygen, which act as a non-intentional perturbing impurity in the lattice. In addition, a vibrational mode located at 598cm-1 related to a forbidden InP-like TO phonon resonance was correlated with oxygen-induced disorder. Photoluminescence at room temperature shows that the high inclusion of oxygen also deteriorates the optical properties of the samples, by introducing non-radiative recombination centers.