Thin Film Solar Deposition Systems
Uniform thin film Indium Tin Oxide (ITO) and Zinc Oxide (ZnO) layers are often created using an ultrasonic spray pyrolysis technique. This unique process demands specialized coating equipment to create necessary coating thickness and morphology, from faceted pyramidal to round-shaped forms.
What is Ultrasonic Spray Pyrolysis? In a high temperature ultrasonic spray pyrolysis process, precursor solutions such as Zinc are sprayed onto a substrate heated to approximately 450-500 degrees Celcius. The solvent is exaporated in transit and the ZnO cyrstalline film is grown on the substrate surface, often soda-lime or other glass. Substrate temperature often dictates the morphology characteristics of the film.
Advantages to Sono-Tek’s FlexiCoat SC spray deposition system for TCO coatings:
- Ultrasonic spray pyrolysis is simple, flexible and cost-effective compared to chemical vapor deposition processes
- Proven TCO coating expertise
- Ultrasonic spray nozzles deposit more uniform layers than other spray methods
- Easy to adjust coating morphology characteristics
- Fully integrated patented ultrasonic nozzle technology and liquid delivery, providing a full coating solution
Alternative low temperature spray pyrolysis processes continue to emerge, with more research and development of chemistries which don’t require heated target substrates. For these processes, Sono-Tek offers our ExactaCoat R&D systems and our FlexiCoat pilot line/batch manufacturing systems. The ExactaCoat and FlexiCoat are proven for spraying oxides, cadmium based suspensions and buffer layer chemistries in thin film solar production as well.
(Left) R&D: ExactaCoat Benchtop System and the FlexiCoat Inline Coating System