X-ray powder diffraction, phase transitions and optical characterization of the Cu(In1-xGax)3Te5 semiconducting system

• Published in: Journal of alloys and compounds Vol. 393; no. 1-2; pp. 100 - 104
• Main Authors: GUEVARA, R, MARIN, G, DELGADO, J. M, WASIM, S. M, RINCON, C, SANCHEZ PEREZ, G
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier 03.05.2005
• Subjects: Exact sciences and technology; Physics; Crystal growth; Cubic lattices; Band structure; Powders; Semiconductor materials; Tetragonal lattices; Phase transformations; Semiconductors; Optical transition; X-ray diffraction; Composition effect; Differential thermal analysis; XRD; Energy gap; Solid solutions; Chalcopyrite structure; Light absorption; Absorption spectra; Thermal analysis; Copper; Bridgman method; Light absorption and reflection; Ingot
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2004.09.048

Ingots of several compositions of the Cu(In1-xGax)3Te5 semiconducting system were prepared by the Vertical Bridgman technique. X-ray powder diffraction, differential thermal analysis and optical absorption studies were used to characterize the fundamental structural aspects and phase transitions and determine the energy band gap Eo of this alloy system. It is found that a solid solution with a tetragonal chalcopyriterelated structure is formed over the entire range of composition for temperatures below 620 deg C. The parameters a and c at room temperature of the tetragonal unit cell were found to vary linearly with composition x from 6.1639(4) and 12.346(6) A for x = 0, to 5.93231(8) and 11.825(4) A for x = 1. A phase transition to a cubic phase in the whole range of composition was observed above 620 DGC. The energy band gap has been determined to be direct and varies linearly with composition x.