ABSTRACT In the last few year, the photovoltaic solar cell has attracted a great deal of interest among researcher in the world. Because, development of new technologies for solar cell with enhanced efficiency is really a big challenge. With this perspective ,organic photovoltaic is considered an emerging photovoltaic technology with promising properties such as low cost ,flexibility ,light weight And large area manufacturing compatibility. But, stability of such cell is very less. An effective way to improve solar cell efficiency is to use a tandem structure where border part of spectrum of solar radiation is used and the thermalization loss of photon energy is minimized . To use solar radiation more effectively ,stack of multiple photo active layers with complementary absorption spectra in series is used to make a Tandem Solar Cell. This also has prospect of enhancing stability of organic solar cell. My objective is to develop a model of tandem solar cell: Organic-inorganic ,Perovskite On Crystalline Silicon(c-Si). This research aims to study the perovskite solar cell using Methyl ammonium lead iodide as active material and the material of such perovskite. The study sugggested that perovskite solar cell has superior performance. The simulation of a conventional P-N junction solar cell and perovskite cell has been done and verified with the experimental result available in literature. The proposed design composed of perovskite cell as top sub cell and c-Si as bottom sub-cell with silicon based tunnel junction that provides majority carrier recombination between sub cells. As this design is a combination of high and low band gap materials, it overcomes the problem of poor use of solar easier and cheaper which reduces the overall cost. A theoretical model of perovskite on c-si solar cell has been developed. Performance of the proposed solar cell has been studied by varying device parameter , e.g. thickness of different layers and results have been analyzed. Finally, this thesis has been concluded with the future scope of work. Key words: Perovskite, solar cell, Crystalline Silicon, P-N junction, Organic-inorganic