Effects of TiO2 Blocking Layer on Photovoltaic Characteristics of TiO2/Nb2O5 Dye Sensitized Solar Cells.

Abstract

This study reports on the effect of introducing TiO2 compact layer on the photovoltaic characteristics of TiO2/Nb2O5 composite dye sensitized solar cell. The compact layer was deposited by spray pyrolysis technique. It was observed that introduction of 60 nm thick compact layer improved the short circuit current density Jsc,Open circuit voltage Voc, and efficiency of the cell from 4.9 mA/cm2 to 8.2 mA/cm2, 6.8×10-1 V to 7.2×10-1 V and 1.9 % to 3.4 % respectively compared to traditional cell prepared without compact layer. Electrochemical impedance spectroscopy confirmed an increase in recombination resistance from 5.5×101 Ω.cm2 for bare DSSC to 9.0×101 Ω.cm2 for DSSC with compact layer thereby improving electron lifetime of the cells from 2.5×10-4 s to 386.9×10-4 s.