Tomm, Y.; Többens, D.M.; Gurieva, G.; Schorr, S. Crystal Growth and the Structure of a New Quaternary Adamantine Cu□GaGeS4. Crystals2023, 13, 1545.
Tomm, Y.; Többens, D.M.; Gurieva, G.; Schorr, S. Crystal Growth and the Structure of a New Quaternary Adamantine Cu□GaGeS4. Crystals 2023, 13, 1545.
Tomm, Y.; Többens, D.M.; Gurieva, G.; Schorr, S. Crystal Growth and the Structure of a New Quaternary Adamantine Cu□GaGeS4. Crystals2023, 13, 1545.
Tomm, Y.; Többens, D.M.; Gurieva, G.; Schorr, S. Crystal Growth and the Structure of a New Quaternary Adamantine Cu□GaGeS4. Crystals 2023, 13, 1545.
Abstract
Single crystals of quaternary adamantine type Cu•GaGeS4 were grown by chemical vapor transport technique using iodine as transport agent. Dark red transparent crystals grew in a temperature gradient of dT = 900–750 °C. Chemical characterization by X-ray fluorescence showed an off-stoichiometric composition of the Cu•GaGeS4 crystals, in particular a slight Ge-deficit. By X-ray diffraction, Cu•GaGeS4 was found to adopt the chalcopyrite-type structure with the space group I-42d. The cation distribution in this structure was analyzed by multiple energy anomalous synchrotron X-ray diffraction and it was found that Cu and vacancies occupy the 4a site, whereas Ga and Ge occupy the 4b site. The band gap energies of several off-stoichiometric Cu•GaGeS4 crystals were determined by UV-Vis spectroscopy and are in the range of 2.1 to 2.4 eV. A non-linear correlation of the band gap energy with the Ge-content of the compound follows the usual bowing behaviour of semiconductor alloys with a bowing parameter of b = 1.45(0.08).
Keywords
defect-adamantine; quaternary chalcogenide; crystal growth; single crystals; structure; cation distribution; band gap energy
Subject
Chemistry and Materials Science, Electronic, Optical and Magnetic Materials
Copyright:
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