Effect of energy disorder in interfacial kinetics of dye-sensitized solar cells with organic hole transport material.

We describe the kinetic rates for dye regeneration in dye-sensitized solar cells with organic solid hole conductors, taking as a reference the experimental results of Haque et al. (ChemPhysChem 2003, 4, 89). Our model is based on Marcus rates for electron and hole transfer, emphasizing the Gaussian spread of energy levels in the molecular materials involved. We show that the energy disorder implies a broadening of the efficiency of hole transfer with respect to the thermodynamic driving force, as observed experimentally. The model also shows that tunning of the kinetic processes for high efficiency of energy conversion of the solar cell depends critically on the interplay between the reorganization energy and the broadening parameters of the energy distributions.