In this paper, the characteristics of organic bulk heterojunction solar cells have been designed and modeled using MATLAB R2010a version. Here, organic solar cell is considered as a diode and an equivalent circuit is developed with series and shunt resistances to obtain the I-V characteristics of the model. Non-linear equations are obtained in by solving the equivalent circuit model. These non-linear equations are solved using Newton-Raphson method. The theoretical results thus obtained are compared with practical results and an observation made is that are theoretical results are close to the results obtained from fabricated structure.