Abstract Founding new materials and structures for solar cells is a challenge in the photovoltaic field. This work evaluated the effect of the lignin in the photovoltaic activity by compounding with TiO2/lignin as photoanode for the dye sensitized solar cells (DSSC’s). Hybrid films (TiO2/lignin) with different concentrations of lignin (5, 10 and 15%) were deposited by spin coating over commercial TiO2 thin films. The cells were sandwich assembled. The characterizations were done through analysis of absorbance, band gap, x-ray diffraction, morphological and electrical. The lignin at 15% reduced the TiO2 band gap from 3.66 to 2.84 eV, favoring the short current density to 11.06 mA/cm2 and efficiency of 4.65%, an increase of 103.95% compared to the TiO2 structure without lignin.

Abstract A low cost spin coater was constructed in this work for the deposition of thin films of titanium dioxide (TiO2) on conductive substrate of FTO (fluoride doped tin oxide) with application on dye sensitized solar cells. The results showed a 95% precision between the speed values obtained by the software of C#sharp language and the spin values observed directly on the device. The TiO2 films deposited through the spin coater with different angular speeds were characterized by UV-Vis optical spectrum, scanning electron microscopy (SEM), atomic force microscopy (AFM) and electrical measurements on an active area of 0.25 cm2. The DSSCs assembled with the TiO2 films of double layer deposited by the spin coater had an efficiency value of 12.74%, while the cell with a single layer presented 4.05% efficiency. Therefore, it is concluded that the spin coater assembled in this study at low costs successfully can produce TiO2 electrodes for DSSCs.