Structural and luminescence properties of CaxBa1−xGa2S4:Eu2+ chalcogenide semiconductor solid solutions

• Published in: Physica. B, Condensed matter Vol. 478; pp. 58 - 62
• Main Authors: Tagiyev, B.G., Tagiyev, O.B., Mammadov, A.I., Quang, Vu Xuan, Naghiyev, T.G., Jabarov, S.H., Leonenya, M.S., Yablonskii, G.P., Dang, N.T.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2015
• Subjects: Chalcogenide semiconductor; Crystal structure; Lattice parameters; Photoluminescence; Solid solution; Thiogallate; Chalcogenide semiconductor; Solid solution; Lattice parameters; Photoluminescence; Thiogallate; Crystal structure
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2015.08.061

The structural and luminescence properties of chalcogenide semiconductor CaxBa1−xGa2S4 solid solutions (x=0.1–0.9) doped with 7at% of Eu2+ ions were studied at room temperature. It was found, that the crystal structure of CaxBa1−xGa2S4 solid solutions varies with the amount of Ca2+ cations and phase transition from cubic to orthorhombic takes place with increase of x value. CaxBa1−xGa2S4:Eu2+ solid solutions exhibit intense photoluminescence in cyan to yellow spectral region depending on x due to 5d→4f electron–dipole transitions in Eu2+ ions. The peak position of the emission band shifts from 506nm for x=0.1 to 555nm for x=0.9 and the full width at half maximum of the emission band varies from 62nm to 72nm depending on the symmetry of the crystal lattice. The PL excitation spectrum of CaxBa1−xGa2S4:Eu2+ covers the range at half maximum from 310nm to 480nm for x=0.1 and to 520nm for x=0.9. It was shown that long-wavelength shift is caused by influence of the growing crystal field strength on Eu2+ ions.