Thin films of aluminium-doped zinc oxide (ZnO:Al) as heat reflective coatings were prepared by multi-target reactive sputtering using metallic Zn and Al targets. An optimization of Al content and a reduction in oxygen partial pressure were crucial in increasing the carrier concentration Ne and the Hall mobility μ. The ZnO:Al film with the highest Ne achieved the shortest plasma wavelength λp of 1375 nm, which shifted the near-infrared reflectance spectrum closer to the visible region. The high μ reduced the optical absorption and enhanced the reflectance. Moreover, the multi-target system enabled intermittent doping of Al, which was applied to stack multilayers consisting of non-doped and Al-doped ZnO layers. A drop in the refractive indices n above λp for the ZnO:Al layers formed the periodic distribution of n in the thickness direction, which provided a high reflectance zone from 1000 to 1400 nm in wavelength.
|Journal||IOP Conference Series: Materials Science and Engineering|
|Issue number||SYMPOSIUM 6|
|Publication status||Published - 2011 Jan 1|
|Event||3rd International Congress on Ceramics, ICC 2011 - Osaka, Japan|
Duration: 2010 Nov 14 → 2010 Nov 18
ASJC Scopus subject areas
- Materials Science(all)