In this paper, the structure ITO/PEDOT:PSS/P3HT:PCBM/Al was optimized by developing a Matlab program based on the Transfer Matrix Formalism (Inspired by McGehee Group Matlab program) [1]. The program calculates optimal thicknesses of PEDOT and P3HT:PCBM layers giving the best short circuit current (JSC) value. Simulation results show clearly an improvement in optical performances for the optimized organic solar cell. Indeed, the energy dissipation profile (Q) is maximized and confined in the active layer which contributes to improve absorption efficiency ηA. This is confirmed by a clear improvement in the fraction of light absorbed in the organic cell after thicknesses optimization.