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Volume 5, Issue 5
Res. Rev. J Mat. Sci. 2017
ISSN: 2321-6212
Advanced Materials 2017
September 07-08, 2017
September 07-08, 2017 | Edinburgh, Scotland
Advanced materials & Processing
11
th
International Conference on
Atomically resolved structure of luminescent ZnkIn
2
O
3+k
J. García-Fernández
1
, A. Torres-Pardo
1
, J. Ramirez-Castellanos
1
, J. M. González-Calbet
1
, A. Cremades
1
and
J. Piqueras
2
1
Departamento de Química Inorgánica, Universidad Complutense de Madrid, Spain
2
Departamento de Física de Materiales, Universidad Complutense de Madrid, Spain
I
ndium zinc oxides (IZOs) have attracted the interest due to their physical properties and high chemical stability. These materials
constitute a large field of research due to its applications as transparent electrodes in transistors, flat panel displays, solar cells,
sensors and photocatalysis properties. In this work, several terms of the homologous series ZnkIn2O
3
+
k with 3≤k≤13 materials were
prepared by the ceramic method. The microstructure of the materials has been elucidated by means of X-ray Diffraction (XRD), high-
resolution transmission electron microscopy (HRTEM and STEM) and Raman spectroscopy. Additionally, luminescence properties
were measured by cathodoluminescence in a scanning electron microscope. The structure can described based on a hexagonal
symmetry, with R-3m space group for those terms with odd k, and P63/mmc for k even, although overlap of the diffraction maxima
occurs for higher members of the series. HRTEM images show these materials are formed by the ordered intergrowth of layers
of InO
2
- octahedral sharing edges with InZnkOk+1+ blocks stacked perpendicularly to the c-axis of the crystal, where zinc and
indium occupy tetrahedral and trigonal bipyramid sites. The existence of extended defects such as twins, dislocations and disordered
intergrowths were also observed. TEM in High Angle Annular Dark Field (HAADF) and Annular Bright Field (ABF) modes show
the indium and zinc distribution along [1-10] and [010] zones axes. The characteristic modulation of this homologous series (a zigzag
pattern) is also visualized. Cathodoluminescence (CL) measurements show the existence of a main emission band centered at 1.75 eV,
associated to Zn vacancies. The variation of the intensity and width of the band depends on the chemical composition of the material.
These results suggest that physical properties can be tailored for technological applications depending on the material composition.
jrcastel@quim.ucm.esRes. Rev. J Mat. Sci. 2017, 5:5
DOI: 10.4172/2321-6212-C1-006