Different photoelectrochemical methods such as photocurrent spectroscopy, uv-laser transient and locodynamic uv-laser scanning experiments were carried out to characterize the Ti/TiO2 system. All measurements were carried out at high local resolution of Ti single grains of known crystallographic orientation. The experimental findings clearly prove that the Gartner/Butler model is insufficient for description of the i(ph)(d(lay)) and i(ph)(U) behaviour of ultrathin amorphous TiO2 films. Both the effect of multiple internal reflections and the influence of the recombination efficiency r(E) must be considered. For this, a complete model is presented and discussed. Consideration of all three parts of this model (Gartner, optics r(E)) allows for a complete interpretation of the experimental findings enabling determination of both electronic and optical layer properties. Both the optical (refractive index, absorption coefficient) and the electronic layer properties (defect state density N-D and permittivity number epsilon(0) show a significant dependence on the orientation of the substrate grains.