After a brief state of art of the challenges of renewable energy and more sepcifically of the solar cells, the place of organic solar devices will be discuss in front of competitive technology such as Perovskite or CIGS. Indeed organic solar cells reveal numerous advantages competiting with higher efficiency devices. Despite that, numerous challenges are emerging with the constant increase of the performance of organic solar cells (OSC); the optimization at each steps of the electronic processes becomes critical. We will pay a specific attention to the charges collection at the electrode and more specifically at the anodic side of the device emphasis the energetic leveling of each material envolve.