The thin film with optimized condition was deposited on the
cleaned FTO as the blocking layer. Since the TiCl4 treatment is the
common method for blocking layer creation in DSSC, we compared
TiCl4 treatment as a blocking layer with ZnO blocking layer, sepa-
rately. For this purpose, in one cell only the TiCl4 used as blocking
layer and in another one the ZnO thin film just was used as a
blocking layer. For TiCl4 treatment FTO was immersed in 40 mM of
TiCl4 aqueous solution at 70 C for 30 min. The commercial past
containing 20 nm TiO2 was deposited on FTO with and without
blocking layer and FTO with TiCl4 treatment by print screen tech-
nique and was dried at 120 C for 6 min. After that films were
calcined at 450 C for 30 min. In order to dye absorption films had
been immersed in the N719 dye solution for 24 h. Dye-anchored
films were rinsed with acetonitrile to remove the accumulated
dye on the surface. The counter electrode was prepared by coating
H2PtCl6 on FTO glass substrate and the surlyn was used as a spacer
between the electrodes. Then the counter electrode and TiO2
working electrode were putted together. Finally the assembled cell
gets filled with the electrolyte and sealed.