Phthalocyanine-Sensitized Nanostructured TiO₂ Electrodes Prepared by a Novel Anchoring Method

Abstract

A novel method for anchoring phthalocyanines substituted with ester groups onto nanostructured TiO2 films is described. Such phthalocyanines did not adsorb on nanostructured TiO2 film by the ordinary methods. In our new method, the TiO2 film is pretreated with (CH3)3COLi to change the surface hydroxyl groups (−OH) into oxygen anions (−O-), thus making the surface more reactive toward the ester functionalities of the dye. The dye can then be anchored onto the semiconductor surface through the produced carboxylate group(s). The amount of anchored dye on the semiconductor shows a dependence on both the time of base treatment and the time of dye treatment. Electrodes treated with the free base phthalocyanine and zinc phthalocyanine were characterized by absorption spectroscopy, photocurrent action spectroscopy, and photocurrent−photovoltage measurements. The homogeneous blue-green color and the absorption bands in the far-red region are indicative of an attachment of the dye on TiO2 film. A monochromatic incident photo-to-current conversion efficiency of 4.3% was achieved at 690 nm for a cell where the base-treated electrode was treated with ZnPcBu.

A New Unsymmetrical Zinc Phthalocyanine as Photosensitizers for Dye-sensitized Solar Cells

“…The typical phthalocyanines explored for sensitization of wide-band gap are free base or metallic ones substituted by carboxylic or sulphonic acid groups for attachment to the semiconductors surface. 16,17 The presence of carboxylic acid act as electron acceptors for the study of photoinduced electron transfer processes as well as grafting onto nanocrystalline TiO 2 .…”

Study of the Effect of Substitution on Phtalocyanine Based Compounds for Photovoltaic Application

“…In fact, these molecules exhibit very high extinction coefficients around 600 nm are considered very good near infrared sensitizers. Additionally, by making use of infrared light, the solar heating of the buildings is reduced, Thereby reducing the demand and power consumption of the air conditioning units [10][11][12][13]. Moreover, the structures of Pc and MPc can be easily modified without significantly changing their stability and processability.…”

Synthesis and Characterization of Peripherally Ferrocene-modified Zinc Phthalocyanine for Dye-sensitized Solar Cell

“…12 Dye adsorption onto TiO2 electrode was carried out from benzonitrile solution in order to minimize the aggregate formation which tends to highly decrease the performance of device. The spectrum of the ZnPc-Fc adsorbed onto TiO2 electrode ( Figure 2b) shows distinctive appearance of the aggregate Q-band at 648 nm with the monomer Q-band at 695 nm that was found to be red-shifted by 7 nm in comparison with that of the dye in benzonitrile solution, revealing a strong interaction between the dye and the semiconductor surface.…”