The characterizations (i.e., film adhesion, optical reflectivity, illumination aging and anti-corrosion behavior) should be considered for the metallic thin film served as a candidate of autolamp materials. The characterizations of three candidates (i.e., sputtered Al-0.11 wt.% Sc, sputtered pure Al, and thermally evaporated pure Al) have been investigated and compared. The sputtered Al-0.11 wt.% Sc film performed much better than any of the other two regarding the characterizations concerned. Examining through AFM, the sputtered Al-0.11 wt.% Sc revealed better surface property (including flatness and smoothness) than the others. Excellence in surface properties and optical reflectivity for the Al-0.11 wt.% Sc may arise from grain refinement in the film. Under long-term illumination, the films led to grain growth and hillocks formation. This illumination aging degraded the surface properties and optical reflectivity of the films, especially for the pure Al films. The sputtered Al-0.11wt.%Sc revealed more corrosion-resistance than the other films in 5% NaCl solution regardless whether or not under illumination aging.
- Al-Sc films