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.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► We model the concentration dependent bimolecular recombination coefficient. ► Open circuit voltage model of organic solar cell based on hopping transport. ► Open circuit voltage depends on light intensity, temperature and material disorder. ► We investigated the deviation of open circuit voltage from linear dependence on temperature.