Hopping transport of electrons in dye-sensitized solar cells

A calculation of the chemical diffusion coefficient of electrons, D-n in dye-sensitized solar cells, is presented, framework of the hopping model, where electron transport occurs by direct transitions between localized states in an exponential distribution. The Fermi-level dependence of D-n in the transport energy approximation is exactly the same as that in the multiple trapping model, but there are differences concerning the meaning of the parameters governing electron transport and the values of relevant energy levels inferred from experiments. The hopping model appears to describe well the experimental data of D-n from high-efficiency dye solar cells at various temperatures.