Electrodeposition of inorganic compound thin films in the presence of certain organic molecules results in self-assembly of various hybrid thin films with new properties. Examples of new discoveries by the authors are reviewed, taking cathodic formation of a ZnO/dye hybrid as the leading example. Hybridization of eosinY leads to the formation of highly oriented porous crystalline ZnO as the consequence of dye loading. The hybrid formation is a highly complicated process involving complex chemistry of many molecular and ionic constituents. However, electrochemical analyses of the relevant phenomena indicate the possibility of reaching a comprehensive understanding of the mechanism, giving us the chance to further develop them into industrial technologies. The porous crystals are ideal for photoelectrodes in dye-sensitized solar cells. As the process also permits the use of non-heat-resistant substrates, the technology can be applied for the development of colorful and light-weight plastic solar cells.

Electrodeposition of Inorganic/Organic Hybrid Thin Films

Cathodic electrodeposition of oxide semiconductor thin films and their application to dye-sensitized solar cells

Mechanism of cathodic electrodeposition of zinc oxide thin films from aqueous zinc nitrate baths

Cathodic electrodeposition in an aqueous mixed solution of zinc nitrate and water-soluble tetrasulfonated metallophthalocyanines (TSPcMs), in which M = Zn(II) (TSPcZn), Al(III)[OH] (TSPcAl), or Si(IV)[OH]2 (TSPcSi), resulted in a self-assembled growth of zinc oxide (ZnO) thin films whose surface is modified by TSPcMs. It has been found that the adsorption of TSPcM onto the growing surface of ZnO strongly affects the crystal growth and the orientation of the ZnO crystallites. The effect was most prominently seen with TSPcSi, creating a film looking like stacking disks aligned perpendicular to the substrate. Crystallographic studies by X-ray diffraction and TEM observation coupled with the selected area electron beam diffraction have revealed that thin platelike crystals, whose planes and edges correspond to the (002) and (100) crystal faces, respectively, are aligned in the same orientation around the c-axis within the stacks. The evolution of this unique structure is interpreted as arising from the prefer...

Anna F. Brajter

Papers

Mechanisms of Zr(IV) and La (III) catalysis of the reduction of nitrate at mercury

Selective electrocatalytic method for the determination of nitrite