Ultrasonic Spray Pyrolysis for Depositing TCO
Ultrasonic spray pyrolysis equipment for depositing TCO chemistries.
Uniform thin film Indium Tin Oxide (ITO), Aluminum Doped Zinc Oxide (AZO), Zinc Oxide (ZnO), and Fluorine Doped Oxide layers are often created using an ultrasonic spray pyrolysis technique. This unique process demands specialized coating equipment to create necessary coating thickness and morphology, spraying corrosive solutions in a high temperature environment.
In a high temperature ultrasonic spray pyrolysis process, precursor solutions such as Aluminum Zinc Oxide are sprayed onto a substrate heated to approximately 300-500 degrees Celsius. The solvent is evaporated in transit and the ZnO crystalline film is grown on the substrate surface, often soda-lime or other glass. Substrate temperature often dictates the morphology characteristics of the film.
Transparent Conductive Oxides (TCOs) are core functional materials widely used in optoelectronic devices, including solar cells, touch screens, and optoelectronic sensors, due to their unique combination of high optical transparency and excellent electrical conductivity. Ultrasonic spray pyrolysis (USP) has emerged as a low-cost, high-efficiency, and scalable atmospheric-pressure deposition technology for fabricating high-performance TCO thin films, standing out from conventional vacuum-based deposition methods such as sputtering and evaporation.
The working principle of USP is straightforward and controllable. The technology utilizes high-frequency ultrasonic vibration ranging from 20 kHz to 2 MHz to atomize TCO precursor solutions, typically composed of soluble metal salts and dopant reagents, into uniform micron or submicron aerosol droplets. These fine, low-velocity droplets are uniformly transported onto a preheated substrate maintained at 300–500 °C. Upon contacting the hot substrate, the droplets undergo sequential solvent evaporation, solute precipitation, thermal decomposition, and in-situ sintering, ultimately forming dense, crystalline, and homogeneous TCO thin films such as FTO, AZO, and ITO.
Compared with traditional pneumatic spray pyrolysis, USP exhibits prominent technical advantages. It produces highly uniform droplets with consistent particle size, effectively eliminating film thickness fluctuation and surface defects, which significantly improves the optical and electrical uniformity of TCO coatings across large-area substrates. Additionally, the low solution flow rate of USP reduces precursor waste, realizing economical material utilization. Most importantly, the atmospheric operating environment eliminates the need for expensive vacuum equipment, greatly lowering production costs and simplifying operational procedures.
Furthermore, USP enables convenient and precise doping regulation by simply adjusting the dopant concentration in the precursor solution, which effectively modulates the carrier mobility and conductivity of TCO films. With its simple setup, easy process adjustment, and excellent scalability for large-area coating, ultrasonic spray pyrolysis has become a promising industrial and laboratory fabrication technique for high-quality, low-cost TCO thin films, supporting the rapid development of optoelectronic and new energy industries.
About Cheersonic
Cheersonic is the leading developer and manufacturer of ultrasonic coating systems for applying precise, thin film coatings to protect, strengthen or smooth surfaces on parts and components for the microelectronics/electronics, alternative energy, medical and industrial markets, including specialized glass applications in construction and automotive.
The Company’s solutions are environmentally-friendly, efficient and highly reliable, and enable dramatic reductions in overspray, savings in raw material, water and energy usage and provide improved process repeatability, transfer efficiency, high uniformity and reduced emissions.
Cheersonic’s growth strategy is focused on leveraging its innovative technologies, proprietary know-how, unique talent and experience, and global reach to further develop thin film coating technologies that enable better outcomes for its customers’ products and processes. For further information, visit https://cheersonic-liquid.com/.
