Donor/Acceptor Heterojunction Organic Solar Cells

The operation and the design of organic solar cells with donor/acceptor heterojunction structure and exciton blocking layer is outlined and results of their initial development and assessment are reported. Under halogen lamp illumination with 100 mW/cm(2) incident optical power density, the devices exhibits an open circuit voltage V-OC = 0.45 V, a short circuit current density J(SC) between 2 and 2.5 mA/cm(2) with a fill factor FF approximate to 50%, an external quantum efficiency (electrons/s over incident photons/s) EQE approximate to 5% and a power conversion efficiency of about 0.5%. Measurements of the photoelectrical characteristics with time are also reported, confirming that non encapsulated organic solar cells have limited stability in ambient atmosphere.