AVS 53rd International Symposium
    Thin Film Thursday Sessions
       Session TF-ThP

Paper TF-ThP13
Surface Modification of Porous Nanocrystalline TiO2 Films for Dye-Sensitized Solar Cell Application by Various Gas Plasma

Thursday, November 16, 2006, 5:30 pm, Room 3rd Floor Lobby

Session: Thin Film Poster Session
Presenter: Y.-S. Kim, Korea University
Authors: Y.-S. Kim, Korea University
K.-J. Kim, Korea University
Y.H. Lee, KIST, Korea
Correspondent: Click to Email
Dye-sensitized solar cells (DSSCs) have been attracting much attention because solar cells are clean, renewable and of low-cost. Many research groups make an effort to enhance photocurrent by using the modification of dye, electrolyte, and TiO@sub2@ films. In this study, cold plasma treatment was used in order to modify TiO@sub2@ films. Cold plasma treatment is a very effective technology in the surface modification for a variety of materials because the surface can be modified without affecting the bulk properties of the materials. The influence of plasma treatment of TiO@sub2@ film on the photoelectric performance of DSSC was investigated. Treatment parameters include kinds of gases, plasma power, and gas pressure. In order to modify TiO@sub2@ surface, we used different ion species such as O@sub2@, N@sub2@, Ar, H@sub2@ and CF@sub4@. After various gas plasma treatment, stoichiomertric changes of TiO@sub2@ films were observed. Short-circuit photocurrent (Jsc), open-circuit voltage (Voc) and the amount of adsorbed dye for DSSCs were measured. As a result, the solar-to-electricity conversion efficiency of the O@sub2@ and N@sub2@ treated cell increased by 10-15% in comparison with untreated cell. On the other hand, solar energy conversion efficiency of CF@sub4@ plasma treated cell decreased drastically. The increased amount of adsorbed dye on the TiO@sub2@ film was measured by UV/Vis absorption spectroscopy. Modified TiO@sub2@ surfaces by plasma treatment were characterized using analytical instruments such as X-ray photoelectron spectroscopy (XPS), Near-edge X-ray absorption fine structure (NEXAFS) and Raman spectroscopy. The improved performance of DSSCs by plasma treated TiO@sub2@ film was attributed to the removal of carbon contaminants, reduction of oxygen vacancies, and the enhancement of bond strength between TiO@sub2@ film and dye.