Optical, structural and lattice dynamical properties of epitaxial Zn1 − yMgySxSe1 − x layers grown by metalorganic vapour phase epitaxy

• Published in: Journal of crystal growth Vol. 159; no. 1-4; pp. 21 - 25
• Main Authors: Hamadeh, H., Söllner, J., Hermans, J., Küster, U., Woitok, J., Geurts, J., Bollig, B., Heuken, M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 02.02.1996; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Ii-vi semiconductors; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Physics; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Inorganic compounds; Epitaxial layers; Semiconductor materials; Organometallic compounds; Transition element compounds; Photoluminescence; Binary compounds; VPE; Zinc Selenides sulfides; Experimental study; Thin films; Solid solutions; Lattice dynamics; Chemical composition; SEM; Quaternary compounds; Heterostructures; Magnesium Selenides sulfides
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/0022-0248(95)00866-7

The optical, structural and lattice dynamical properties of Zn1 − yMgySxSe1 − x epilayers grown by low pressure metalorganic vapour phase epitaxy were investigated. The composition of these layers, determined by electron probe microanalysis, was varied in the range of 0 ≤ x, y ≤ 0.2. Photoluminescence measurements in the temperature range between 14 and 300 K were performed. The alloy broadening of the bandedge emission depending on the composition of the layer was calculated on the basis of a binomial statistical model. The comparison between the measured bandedge photoluminescence halfwidth and the calculated alloy broadening showed high composition homogeneity for samples with low sulphur and magnesium contents (x, y < 0.16) and poor homogeneity for samples with large x and y. Scanning transmission electron microscopy investigations showed a low density of structural defects in samples with narrow bandedge emission and low x and y, whereas a high defect density was detected in samples with large bandedge broadening. These results are correlated to the observation of symmetric and asymmetric profile shapes of the broadened X-ray rocking curves, respectively. Four-mode behaviour of the ZnMgSSe lattice vibrations was testified by Raman measurements.