Structure of AgI-doped Ge-In-S glasses: Experiment, reverse Monte Carlo modelling, and density functional calculations

Journal Article · Wed Aug 15 04:00:00 EDT 2012 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2012.03.046· OSTI ID:22131093

Chrissanthopoulos, A. ^[1]; Jovari, P. ^[2]; Kaban, I. ^[3]; Gruner, S. ^[4]; Kavetskyy, T. ^[5]; Borc, J. ^[6]; Wang, W.; Ren, J.; Chen, G. ^[7]

---

1. Foundation for Research and Technology Hellas, Institute of Chemical Engineering and High Temperature Chemical Processes (FORTH/ICE-HT), PO Box 1414, Patras, GR-26504 (Greece)
2. Research Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, PO Box 49, Budapest, H-1525 (Hungary)
3. IFW Dresden, Institute for Complex Materials, PO Box 270116, Dresden, D-01171 (Germany)
4. Chemnitz University of Technology, Institute of Physics, D-09107, Chemnitz (Germany)
5. Solid-State Microelectronics Laboratory, Drohobych Ivan Franko State Pedagogical University, 24 I.Franko Str., Drohobych 82100 (Ukraine)
6. Department of Applied Physics, Lublin University of Technology, 38 Nadbystrzycka Str., Lublin 20-618 (Poland)
7. School of Materials Science and Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China)

We report an investigation of the structure and vibrational modes of Ge-In-S-AgI bulk glasses using X-ray diffraction, EXAFS spectroscopy, Reverse Monte-Carlo (RMC) modelling, Raman spectroscopy, and density functional theoretical (DFT) calculations. The combination of these techniques made it possible to elucidate the short- and medium-range structural order of these glasses. Data interpretation revealed that the AgI-free glass structure is composed of a network where GeS{sub 4/2} tetrahedra are linked with trigonal InS{sub 3/2} units; S{sub 3/2}Ge-GeS{sub 3/2} ethane-like species linked with InS{sub 4/2}{sup -} tetrahedra form sub-structures which are dispersed in the network structure. The addition of AgI into the Ge-In-S glassy matrix causes appreciable structural changes, enriching the Indium species with Iodine terminal atoms. The existence of trigonal species InS{sub 2/2}I and tetrahedral units InS{sub 3/2}I{sup -} and InS{sub 2/2}I{sub 2}{sup -} is compatible with the EXAFS and RMC analysis. Their vibrational properties (harmonic frequencies and Raman activities) calculated by DFT are in very good agreement with the experimental values determined by Raman spectroscopy. - Graphical abstract: Experiment (XRD, EXAFS, RMC, Raman scattering) and density functional calculations are employed to study the structure of AgI-doped Ge-In-S glasses. The role of mixed structural units as illustrated in the figure is elucidated. Highlights: Black-Right-Pointing-Pointer Doping Ge-In-S glasses with AgI causes significant changes in glass structure. Black-Right-Pointing-Pointer Experiment and DFT are combined to elucidate short- and medium-range structural order. Black-Right-Pointing-Pointer Indium atoms form both (InS{sub 4/2}){sup -} tetrahedra and InS{sub 3/2} planar triangles. Black-Right-Pointing-Pointer (InS{sub 4/2}){sup -} tetrahedra bond to (S{sub 3/2}Ge-GeS{sub 3/2}){sup 2+} ethane-like units forming neutral sub-structures. Black-Right-Pointing-Pointer Mixed chalcohalide species (InS{sub 3/2}I){sup -} offer vulnerable sites for the uptake of Ag{sup +}.

• OSTI ID: 22131093
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Vol. 192; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ABSORPTION SPECTROSCOPY
DENSITY FUNCTIONAL METHOD
DOPED MATERIALS
FINE STRUCTURE
GLASS
INDIUM
IODINE
MONTE CARLO METHOD
RAMAN EFFECT
RAMAN SPECTROSCOPY
SILVER IODIDES
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY