Effect of TiO2 blocking layer on photovoltaic performances of solar cells sensitized with N719

In this study we employ a synthetic dye (ruthenizer 535-bisTBA (N719)) as a sensitizer for dye solar cells without $(Cell_{NBL}$) and based blocking layer $(Cell_{BL}$). The photoanodes prepared with doctor blade were analyzed by X’pert Pro X-ray diffractometer to identify the anatase structure. The optical properties of the dyes and sensitized photoanodes in the region 400–800 nm were determined by UV–Vis spectrophotometer. The current-Voltage (I-V) characteristics of realized DSSCs were measured in AM1.5 solar irradiance spectra at ambient temperature using Keithley 6517A multimeter. The blocking layer leads to the enhancement of photoconversion efficiency (PCE) by physical separation of the substrate FTO and the electrolyte. There is a remarkable increase of Jsc which reaches 8.88 mA.cm$^{-2}$ compared to the cell without blocking layer, leading an efficiency of 3.9% under power radiation equal to 100mWcm$^{-2}$. The obtained results show a simple way to improve the performance of dye-sensitized solar cells based on TiO2