The influence of scattering has been identified by simulations of dye photophysical measurements on both ZrO2 and TiO2 photoanodes for dye-sensitized solar cells. 3. Because we assume an ideal sample, the influence of band bending on charge populations is not directly included. The thickness of space charge layer is estimated as 20 nm in experiments, but this is likely to be higher as potential increases. However, it is unclear what a space charge layer width means for a sample whose surface rms roughness is ~20 nm on top of ~10 nm rms rough FTO. How the space charge layer evolves under illumination must be connected to the changes shown in Figures and, but further comparisons are not possible without modeling more realistic crystals.