Structural and optical properties of a mechanically alloyed thermoelectric lamellar SnSeS solid solution
Abstract: A chalcogenide SnS2-xSex alloy with x = 1, synthesized by high-energy mechanical alloying, was characterized by high-resolution transmission electron microscopy, X-ray diffraction, differential scanning calorimetry, Raman spectroscopy, and UV-Vis absorbance. The obtained alloy powder was a lamellar solid solution with nanometric crystalline domain sizes and several types of defects such as stacked faults, discordances, crystal fractures, and local atomic disorders. All of these microstructural features lead to the manifestation of different optical and vibrational properties of this extensively deformed nanostructured sample. Raman spectroscopic measurements suggested a two-mode vibration indicating how the S and Se atoms were distributed in the crystalline lattice. The UV-Vis absorbance spectrum showed multiple bandgaps at 1.99, 2.60, 3.09, 3.66, and 4.56 eV that may well be described as direct allowed interband electronic transitions suggesting inhomogeneous strain and domains. Published under license by AIP Publishing.
Author(s): Melquiades, MO; de Oliveira, LS; Rebelo, QHF; Chaudhuri, P; Leite, ER; Triches, DM; de Souza, SM
JOURNAL OF APPLIED PHYSICS
Volume: 126 Published: OCT 7 2019
DOI: 10.1063/1.5120033
