Dye adsorption on single crystal oxide semiconductors as a model for dye sensitized solar cells

COLL 457

Bruce A. Parkinson, Bruce.Parkinson@colostate.edu1, Mark T. Spitler2, and Yunfeng Lu1. (1) Department of Chemistry, Colorado State University, Fort Collins, CO 80523, (2) Solar Energy Research Institute, 1617 Cole Blvd., Golden, CO 80402
We have studied the adsorption and desorption behavior of a series of structurally similar dicarboxylated thiacyanine sensitizing dyes on a number of low index surfaces of titatium dioxide. Rutile (110) and (001) and anatase (101) and (001) surfaces were all studied. Absolute coverages were measured using photochronocoulometry. Photocurrent spectroscopy indicated that many of the dyes aggregate on the surface and this tendency to aggregate was dependent on the surface structure. The adsorption isotherms for many of the dyes were measured as well as adsorption and desorption rates. It was found that the desorption of the dye was strongly influenced by the identity of the reducing agent used as the regenerator. Desorption was fast when hydroquinone was used as the regenerator whereas little or no desorption was seen using iodide. The kinetics of desorption was modeled taking into account dyes bound to the surface by either one or two carboxylate groups.
 

Interfacial Electron Transfer and Solar Energy Conversion: From Molecules to Nanomaterials
8:40 AM-12:00 PM, Thursday, April 10, 2008 Morial Convention Center -- Rm. 226, Oral

Division of Colloid & Surface Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008