Negative permittivity of ZnO thin films prepared from aluminum and gallium doped ceramics via pulsed-laser deposition

M. A. Bodea, Johannes Kepler University of Linz
G. Sbarcea, Johannes Kepler University of Linz; Polytechnic University of Bucharest; Natl Inst Res & Dev Elect Engn ICPE
Gururaj V. Naik, Birck Nanotechnology Center, Purdue University
Alexandra Boltasseva, Birck Nanotechnology Center, Purdue University; Technical University of Denmark; University of Erlangen Nuremberg
T. A. Klar, Johannes Kepler University of Linz
J. D. Pedarnig, Johannes Kepler University of Linz

Abstract

Aluminum and gallium doped zinc oxide thin films with negative dielectric permittivity in the near infrared spectral range are grown by pulsed laser deposition. Composite ceramics comprising ZnO and secondary phase Al2O3 or Ga2O3 are employed as targets for laser ablation. Films deposited on glass from dense and small-grained ceramic targets show optical transmission larger than 70 % in the visible and reveal an onset of metallic reflectivity in the near infrared at 1100 nm and a crossover to a negative real part of the permittivity at approximately 1500 nm. In comparison to noble metals, doped ZnO shows substantially smaller losses in the near infrared.

Discipline(s)

Nanoscience and Nanotechnology