Fabrication of a low cost microcontroller based spray pyrolysis system for thin film deposition

Spray pyrolysis technique confers a spontaneous way to deposit thin film on flexible substrates with minimum consumption of desired material simply by adding it with the spray solution. The constituent units of the simplified spray pyrolysis technique are spray-dry chamber, a temperature controlling unit, a spray-dry controlling unit and an exhaust gas emission unit. The aim of this work is to simplify the fabrication method of the system and minimize the cost. On this regard, a handmade wooden chamber, an electrical heater with temperature controller and exhaust fans are used in this system which are available in local market. A servo motor interfaced with a microcontroller and a LCD display is used for the spray-dry unit where the time is set by using a matrix keyboard. Eventually, Zinc Oxide thin film is obtained on a glass substrate by using this system and its optical property is observed in a Spectrophotometer after completing the fabrication of the system. An easy fabrication process with the user friendly equipment make this system simple, easy to handle and maintain with less mechanical hazards.