Ultrafast dynamics of the dielectric functions of ZnO and BaTiO{sub 3} thin films after intense femtosecond laser excitation

Journal Article · Fri Feb 07 00:00:00 EST 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4864017· OSTI ID:22278135

Acharya, S.; Seifert, G. ^[1]; Chouthe, S.; Graener, H. ^[2]; Böntgen, T.; Sturm, C.; Schmidt-Grund, R.; Grundmann, M. ^[3]

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1. Centre of Innovation Competence SiLi-nano, Martin-Luther-Universität Halle-Wittenberg, Karl-Freiherr-von-Fritsch-Str. 3, D-06120 Halle (Germany)
2. Physics Institute, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 3, D-06120 Halle (Germany)
3. Institute for Experimental Physics II, Universität Leipzig, Linnestraße 5, 04103 Leipzig (Germany)

The ultrafast carrier dynamics of epitaxial ZnO and BaTiO{sub 3} thin films after intense excitation at 3.10 eV and 4.66 eV photon energy has been studied by femtosecond absorption spectroscopy. Modelling the transient transmission changes on the basis of spectroscopic ellipsometry data and pertinent equilibrium model dielectric functions extended by additional terms for the effects at high carrier density (P-band luminescence and stimulated emission from electron-hole-plasma), a self-consistent parameterized description was obtained for both materials. Excited carrier lifetimes in the range of ≈2 to ≈60 ps and long-lived thermal effects after several hundred ps have been identified in both materials. These findings form a reliable basis to quantitatively describe future femtosecond studies on ZnO/BaTiO{sub 3} heterolayer systems.

• OSTI ID: 22278135
• Journal Information: Journal of Applied Physics, Vol. 115, Issue 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION SPECTROSCOPY
CARRIER DENSITY
CARRIER LIFETIME
CHARGE CARRIERS
COMPUTERIZED SIMULATION
DIELECTRIC MATERIALS
ELLIPSOMETRY
EPITAXY
EXCITATION
HETEROJUNCTIONS
LUMINESCENCE
PHOTONS
SOLID-STATE PLASMA
STIMULATED EMISSION
TEMPERATURE DEPENDENCE
THIN FILMS
TITANATES
ZINC OXIDES