Tail states recombination limit of the open circuit voltage in bulk heterojunction organic solar cells

An analytical theory is presented for bimolecular recombination through tail states and open circuit voltage in bulk heterojunction organic solar cells. It is developed rigorously using the hopping transport and the drift diffusion theory. Based on the proposed model, a variety of temperature, energy disorders of the material and illumination intensity dependencies of the open circuit voltage can be well described. Good agreement between the calculation and recent experimental data is found. (C) 2011 Elsevier B. V. All rights reserved.