[en] Full text: Polymer/inorganic hybrid solar cells have drawn considerable attention as a promising renewable energy source. These hybrid solar cells have several advantages over their pure inorganic counterparts. Hybrid solar cells based on silicon wafers have received great attention due to the possibility of reducing its effective thickness when applied to the traditional photovoltaic devices. In this work, we present the modification of Silicon/poly-3-hexylthiophene (P3HT) interface through the alkylation of the silicon surface for application in Al/Si/P3HT/Au device architecture. Results from X-ray photoelectron spectroscopy (XPS) showed that the attachment of thiophene monomers to the silicon surface was successful, evidenced by the signal attributed to the sulfur group onto the silicon surface. Photophysical experiments showed the reflectance decreased in the presence of the polymer coating. This result indicates that P3HT acts as an anti-reflective coating for silicon. For solar cell applications, Schottky, Si/P3HT, and Si/modifier/P3HT devices were assembled in order to evaluate the photovoltaic properties of the Si/P3HT interface. A similar Voc was measured for all PV devices employing P3HT, indicating that this interface contributes to the photovoltaic response. Devices based on Si wafers modified by thiophene alkylation provided overall energy conversion efficiencies up to 5.7%. (author)