In the past few decades the field of organic electronics particularly organics photovoltaic (OPVs) find wide interest among researchers. It finds many advantages such as light weight, low temperature fabrication requirements, mechanical flexibility, can be fabricated by roll-to-roll process methods. Since, the OPVs are thin film devices the optical absorption and device interfaces are very important factor in deciding the device performance. The optical absorption is dictated by the semiconducting active layer which generates the charge carrier for the effective current generations. The absorption of the active layer can be enhanced by various methods to improve the electron-to-photon conversion ratio. The interface properties play crucial role because the semiconductor generated exciton needs to be splitted and collected effectively at the electrode. This can be effectively achieved by aligning energy level of the active layer, interface layer and electrode. Further, the device efficiency is also correlated with the morphology at the various interfaces which controls the charge carrier flow across the different layers. In the chapter-1, the details about the motivation of the work, generation of the solar cell and the invention of the photovoltaic and then discussed about working principle of OPVs and finally summary of the work is given. In the chapter-2, the materials, methods and characterization technique details are given. In the chapter-3, plasmonic device was designed to enhance the photocurrent density in an inverted bulk heterojunction organic solar cell. Aluminum nanoparticles dispersed in the hole transport layer at the rear end of the device structure are observed to enhance the device performance through multiple effects including enhanced absorption and better charge collection. Modeling and simulations are used to understand the mechanisms of optical transport that underline the enhancements which are experimentally observed. In the chapter-4, the ternary blend system, binary acceptor (PC71BM and ...