A Comparative Study on the Various Blocking Layers for Performance Improvement of Dye-sensitized Solar Cells

In this study, short-circuit preventive layer ( blocking layer) was deposited between conductive transparent electrode and porous TiO2 film in the DSSCs. As blocking layer, we selected the metal-oxide such as TiO2, Nb2O5 and ZnO. The sheet resistance with each different blocking layers were 18 Omega/sq. for the TiO2 , 10 Omega/sq. for the Nb2O5 and 8 Omega/sq. for the ZnO, while the RMS ( Root Mean Square) roughness value of DSSCs were 39.61 nm for the TiO2, 41.84 nm for the Nb2O5 and 36.14 nm for the ZnO respectively. From the results of photocurrent-voltage curves, a sputtered Nb2O5 blocking layer showed higher performance on 2.64% of photo-electrochemical properties. The maximum of conversion efficiency which was achieved under 1 sun irradiation by depositing the blocking layer increased up to 0.56%.