Energy is prime need for the man, initially the use of Energy was limited but with the civilization the consumption of energy for different purposes increased. The sun was fulfilling all the energy needs of human being either directly or indirectly and man was using only renewable sources of energy. The most important being solar energy, which will focus our attention solar energy, is a large, inexhaustible source of energy. It is one of the most promising sources of non-conventional energy sources. Solar energy can utilize by various ways, photovoltaic (PV) convention has its own importance. By means of solar cells light can be directly converted into electricity using PV effect. In future solar cells become an important source of power for providing electrical energy for localized use, particularly in remote areas. In view of the above discussion, to get the maximum conversion efficiency of Amorphous silicon a-Si:H based solar cells, it is necessary to minimize the losses due to the shading of metal grid on the top of the solar cell surface and to increase the absorption of incident photon energy. This will require a conducting and transparent material having wide band gap. A survey of the literature shows that the ZnO semiconductor is found to a suitable material with wide band gap (>3 eV) having high transparency in visible region and high electrical conductivity. Furthermore, the aim of present study is to understand the deposition technique (spray pyrolysis) and to optimize the process parameters so as to get best opto-electronic properties of ZnO thin films.