We are also extensively involved in designing organic photovoltaic solar cells with suitable donor/acceptor counterpart. A new milestone is reached in the field of organic solar cells with the invention of fullerene as a highly efficient acceptor. Organic photovoltaic cells comprising electron rich π-conjugated organic molecules donor and electron deficient acceptor moieties show excellent photoconversion efficiency (PCE). On the basis of ground and excited state electronic structure calculations employing DFT and TDDFT methodologies, we pay particular attention to control the charge transfer and unwanted charge recombination of electrons injected into acceptor with oxidized donor which necessarily guide the PCE of the fabricated devices.