Spray pyrolysis of ZnO thin films for photovoltaic applications: effect of gas flow rate and solute concentration

A study has been undertaken to establish the influence of the principal process variables governing the spray pyrolysis deposition of ZnO thin films on their electrical and optical properties as pertaining to photovoltaic applications. It shows that the temperature at which optimum ZnO thin films can be deposited by spray pyrolysis using a given set of conditions of solute concentration and carrier gas flow-rate cannot be assumed to remain unchanged for other deposition conditions. The study also shows that it is possible to find the necessary deposition conditions for producing optimum films. A methodology is presented that can be used in calculating the substrate temperature, solute concentration, and the carrier gas flow-rate that should be used to obtain films with the best photovoltaic quality possible for a given spraying system and a given type of ionic solution