Extremely adhesive polybithiophene (PBT) films were grown on TiO2 in a new, two-step procedure using a silyl substituted thiophene derivative as a surface coupling agent and a subsequent chemical polymerization process. Electrochemical impedance and photocurrent measurements were carried out in order to achieve information on the semiconducting properties of both materials. When a PET film deposited onto TiO2 is reduced it can be described as a p-type semiconductor with a flatband potential of about 0.65 V (vs. SCE), whereas the n-type semiconductor TiO2 gives a flatband potential of about -0.4 V (vs. SCE). The photocurrent measurements show an anodic photocurrent at wavelength of between 300 and 400 nm and a cathodic photocurrent of between 400 and 600-700 nm, confirming the impedance measurements. The results of the impedance and photocurrent measurements are summarized in a band structure model which explains the behaviour of the semiconductor electrode Ti/n-TiO2/p-PBT.