Modeling and simulation of organic solar cells

We present our investigation of organic solar cells by modeling and simulation after numerically solving Poisson and continuity equations that describe the electric property of semiconductors. Specifically, simulations reveal that Langevin type recombination, which describes the loss mechanism in pristine materials with low mobility, is not proper to predict the performance of BHJ organic solar cells and will lead counterintuitive simulation results. Then, the recombination mechanism has been studied in bulk heterojunction (BHJ) organic solar cells by simulating intensity-dependent current-voltage (J-V) measurements. The simulation results indicate that primary loss mechanism is monomolecular recombination. Moreover, the unbalanced carrier transport in organic solar cells is explored and the simulation suggests that increasing hole mobility is an effective method to improve the performance of organic solar cells.