Growth, structural and optical properties of Pb1-xFeₓTe epitaxial films
UNEC Journal of Engineering and Applied Sciences, vol.5, no.2, pp.98-103, 2025 (Scopus)
- Publication Type: Article / Article
- Volume: 5 Issue: 2
- Publication Date: 2025
- Doi Number: 10.61640/ujeas.2025.1208
- Journal Name: UNEC Journal of Engineering and Applied Sciences
- Journal Indexes: Scopus
- Page Numbers: pp.98-103
- Keywords: band gap, crystal structure, epitaxial films, optical characteristics, SEM, XRD
- Azerbaijan State University of Economics (UNEC) Affiliated: No
Abstract
This paper presents the results of a study on the growth, structural properties, and optical characteristics of Pb1-xFeₓTe (x < 0.05) epitaxial films with thicknesses ranging from 0.5 to 1 µm. The films were grown on BaF2 substrates using the molecular beam epitaxy method under a vacuum of 10-4 Pa, with an additional compensating source of Te vapor during the growth process. Optimal conditions for obtaining structurally high-quality Pb1-xFeₓTe epitaxial films were determined to be: substrate temperature Tsubst = 573–623 K, source temperature Tsourc = 1123–1173 K, tellurium temperature TTe = 410 K, and growth rate Jc = 8–9 Å/s. Structural characterization using XRD confirmed the formation of high structural perfection, and a measured lattice constant of approximately a = 6.37 Å. Surface morphology analysis via scanning electron microscopy SEM revealed that microstructural features, including the formation of lead chalcogenide clusters, are sensitive to growth parameters, particularly substrate temperature and condensation rate. Optical measurements show that increasing the concentration of Fe² ions leads to a decrease in the band gap. This effect is attributed to the formation of localized energy levels within the band gap, associated with the 3d orbitals of Fe.