Fabrication of Custom-Designed and Cost-Effective Spin-Spray Pyrolysis Unit

Abstract

In this paper, an efficient, spin-spray pyrolysis unit is designed and constructed for the deposition of oxide thin films. The system is an effective combination of two independent techniques such as spin and spray methods. The rotation of the substrate by keeping the spray nozzle stationary makes the system unique. The system allows the decomposition of the solution before reaching the substrate. Spin-spray pyrolysis unit is capable of coating thin films on different substrates like float glass, FTO coated glass, and Aluminum coated glass, Teflon, and kepton, of dimensions up to 4-inch diameter, any contour and scalable to industrial applications. Metal oxides like Al2O3, GZO, ZnO etc., can be coated for many applications such as solar cells, thin-film transistors, sensors, etc. The elements required for construction of spray pyrolysis units are a heater, spray nozzle, thermocouple, solution feeding unit, airflow assembly, substrate rotator, and exhaust assembly. The elements of the system are discussed in accordance with the cost estimation. The working principle of each element of the system is explained in a separate block diagram. The system is optimized for deposition of ZnO thin films on a glass substrate and is characterized. The thinfilms can be used for development of TFT’s, heaters, thermistors, piezo-electronics devices, sensors, antireflection coatings and solar cell.