Construction of Solid-State Thin Film Solar Cell by Applying Visible Light-Responsive TiO2 Thin Film Materials

A radio frequency magnetron sputtering (RF-MS) deposition method was employed to prepare visible light-responsive TiO2 thin films (Vis-TiO2) which can absorb visible light above 400 nm and be applied as a working electrode for sandwich-type two-electrode dye-sensitized solar cells (DSSCs). The effects of Cu2O and CuI deposition on the photovoltaic cell performance of these Vis-TiO2/ITO-glass electrodes were also investigated. The Cu2O/Vis-TiO2/ITO-glass electrode exhibited higher photovoltaic cell performance than that without Cu2O deposition, showing that electron injection from the photoexcited Cu2O into the conduction band of the Vis-TiO2 thin film plays an important role in increasing the photovoltaic cell performance. Furthermore, it was found that the deposition of CuI as well as the UV-TiO2 thin film was also effective in enhancing the photovoltaic cell performance of the Vis-TiO2/ITO-glass electrode. To construct solar cells using solid electrolytes, the gelation of a NaI/I2 redox electrolyte was investigated using poly(acrylic acid) partial potassium salt. Finally, it was demonstrated that a DSSC system applying Vis-TiO2/N719/CuI/Au is a promising candidate in the development of unique all solid-type DSSC systems.