Opto-Electrical Simulation of Organic Solar Cells

In this paper the optical and electrical simulation of the organic solar cells are represented. It is shown that the results of optical simulation are consistent with previously calculated ones. Due to interference, the peak amplitude of wave and its position change within the structure and cause the exciton generation to oscillate inside the active layer. Electrical simulation of devices is done and it is seen that the solar cell fill factor decreases with enhancing the thickness due to the increased serial resistance. For the thickness of 90nm the fill factor of solar cell is 75% however by increasing the thickness to the 320nm it decreases to 42%. The effect of active layer thickness on the short circuit current and efficiency in organic solar cells is studied. Comparing our results with experimental data confirms that the model is well simulated the behavior of the Bulk Heterojunction Solar Cells. According to the obtained results from simulations, despite of the increased photon absorption, the power conversion efficiency is reduced by increasing the thickness due to the low mobility of organic materials and non-geminate recombination.