With this ultrasonic spray unit it is possible to homogeneously apply large area layer systems to substrates using pyrolysis or wet spraying. Pyrolysis requires a sufficiently high substrate temperature for the precursor solution so that all components are able to pass into a gaseous state. The layer precipitates onto the substrate through a chemical vapor reaction. After the process of wet spraying the layer material and furthermore a solvent film remains on the substrate. The solvent evaporates when heated afterwards.
Our activities in this field include large area spraying of oxide-ceramics (e.g. aluminum-oxide as passivation layer for photovoltaics) and semiconductors (e.g. ZnO:Al) and spraying of dispersions, for example made of CNTs for manufacturing of transparent conductive layers.
- ultrasonic nozzles (Sono Tek Corp.):
- 120 kHz, Vortex, drop size 19 µm diameter for water
precursor flow rate: up to 1.5 ml/min, circular spray pattern
- 120 kHz, surface nozzle
precursor flow rate: 10 ml/min - 70 ml/min, spray width: 5 - 60 cm
- max. substrate size: up to 156 mm x 156 mm
- max. substrate temperature: 450 °C
- distance nozzle - substrate: up to 200 mm
- atmosphere: air or nitrogen
- movement system for nozzle: nozzle movable in x- and y-direction with max. 200 mm/s