Optical and vibrational properties of (ZnO){sub k} In{sub 2}O{sub 3} natural superlattice nanostructures

Journal Article · Sat May 21 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4950789· OSTI ID:22596996

Margueron, Samuel ^[1]; Pokorny, Jan; Skiadopoulou, Stella; Kamba, Stanislav ^[2]; Liang, Xin ^[3]; Clarke, David R. ^[4]

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1. Laboratoire Matériaux Optiques, Photonique et Systèmes, Université de Lorraine et CentraleSupélec, 57070 Metz (France)
2. Institute of Physics, Czech Academy of Sciences, Na Slovance 2, 182 21 Prague 8 (Czech Republic)
3. School of Materials Science and Engineering, Changzhou University, Changzhou, Jiangsu Province 213164 (China)
4. John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Maryland 02138 (United States)

A thermodynamically stable series of superlattices, (ZnO){sub k}In{sub 2}O{sub 3}, form in the ZnO-In{sub 2}O{sub 3} binary oxide system for InO{sub 1.5} concentrations from about 13 up to about 33 mole percent (m/o). These natural superlattices, which consist of a periodic stacking of single, two-dimensional sheets of InO{sub 6} octahedra, are found to give rise to systematic changes in the optical and vibrational properties of the superlattices. Low-frequency Raman scattering provides the evidence for the activation of acoustic phonons due to the folding of Brillouin zone. New vibrational modes at 520 and 620 cm{sup −1}, not present in either ZnO or In{sub 2}O{sub 3}, become Raman active. These new modes are attributed to collective plasmon oscillations localized at the two-dimensional InO{sub 1.5} sheets. Infrared reflectivity experiments, and simulations taking into account a negative dielectric susceptibility due to electron carriers in ZnO and interface modes of the dielectric layer of InO{sub 2}, explain the occurrence of these new modes. We postulate that a localized electron gas forms at the ZnO/InO{sub 2} interface due to the electron band alignment and polarization effects. All our observations suggest that there are quantum contributions to the thermal and electrical conductivity in these natural superlattices.

• OSTI ID: 22596996
• Journal Information: Journal of Applied Physics, Vol. 119, Issue 19; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BRILLOUIN ZONES
CONCENTRATION RATIO
DIELECTRIC MATERIALS
ELECTRIC CONDUCTIVITY
ELECTRON GAS
ELECTRONS
INDIUM OXIDES
INTERFACES
NANOSTRUCTURES
PERIODICITY
PHONONS
PLASMONS
POLARIZATION
RAMAN EFFECT
REFLECTIVITY
SUPERLATTICES
TWO-DIMENSIONAL SYSTEMS
ZINC OXIDES