Production of thin luminescent films by Chemical Aerosol Deposition Technology (CADT)

CADT is used to produce thin luminescent films of ZnS by pyrolysis of ZnCl2 and CS(NH2)2. SEM-photography and X-ray diffraction studies revealed that under specific experimental conditions polycrystalline ZnS (relative density ≈ 80 %) with a preferential orientation of the c-axis perpendicular to the substrate was obtained. Luminescence was found in ZnS-films doped with proper amounts of Cu and Al. The luminescence yield increased with better diffusion conditions during film growth

Rate control in dual source evaporation

Two-component thin films are deposited in a high-vacuum system from two close sources, heated by an electron beam which is deflected between them. By using quartz-crystal monitors the evaporation rates are measured separately, which is usually considered to be problematical. One rate signal is used to regulate the appropriate deposition rate by controlling the emission current. The other deposition rate is regulated by using the rate signal to control the dwell-time ratio of the electron beam. With this system it is possible to deposit any composition with a good homogeneity, as in the case Gd-Fe and Gd-Co films