Enhanced near-field noise absorption of transparent ZnO nanofilms by Al substitution

Abstract

Transparent Al-doped ZnO (AZO) conductive films were prepared by confocal dc-reactive magnetron sputtering using Zn and Al targets in an Ar/O2 reactive atmosphere. The effect of Al substitution on the near-field radio-frequency (RF) noise absorption of the AZO films was investigated. After a standard short–open–load–through calibration, the near-field RF noise attenuation was measured using a RF microstrip test fixture suitable for quasi-transverse electromagnetic wave propagation. The RF noise absorption capability of the AZO films is enhanced from essentially zero to 26% (4–6 GHz) by doping with 5.9% Al. Surface proximity-induced loss is considered the dominating mechanism in the RF noise absorption of AZO films. The crystal quality and morphology are affected significantly by the substitution of Al in AZO films. Dc conductivities, dielectric properties and optical characterizations are also discussed.

Role of substrate and annealing temperature on the structure of ZnO and AlxZn1−xO thin films for solar cell applications

“…However it is known that for particle size greater than 5 m, S can be wavelength independent [13]. We also assumed that S is wavelength independent since the beam size impinges on larger than 1 mm in the far field.…”

“…Based on the previous literature, Al seems to be a successful and promising doping element for ZnO [8,[10][11][12]. Al can be substitutionally incorporated at the Zn lattice site in the ZnO structure, denoted as AZO [13], to fabricate Al doped ZnO film with high temperature stability and good immunity against hydrogen plasma reduction [14- 2 …”