ZnO thin films have been prepared using several deposition techniques such as pulsed laser deposition [9],
magnetron sputtering [10], spray pyrolysis [11], and sol–gel [12]. Compared to others techniques, spray pyrolysis is
simple, non-vacuum and inexpensive method. Moreover, it is useful for producing large scale films. The quality and
physical properties of films prepared using the spray pyrolysis technique depend on different deposition and postdeposition
conditions such as the nature and concentration of precursor, substrate temperature, spray rate, nozzle to
substrate distance, pressure of carrier gas, and annealing. In these parameters, substrate temperature usually plays a
crucial role in growth of ZnO films. It has been revealed that these conditions have a significant effect on properties
of ZnO based TCO films.