Core–shell nanoporous electrode for dye sensitized solar cells: the effect of shell characteristics on the electronic properties of the electrode

✍ Scribed by Yishay Diamant; Shlomit Chappel; S.G. Chen; Ophira Melamed; Arie Zaban

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 96 KB
• Volume: 248
• Category: Article
• ISSN: 0010-8545
• DOI: 10.1016/j.ccr.2004.03.003

✦ Synopsis

Nanoporous TiO 2 electrodes coated with a thin layer of various wide band gap materials were tested in dye sensitized solar cells (DSSCs). Using Nb 2 O 5 , ZnO, SrTiO 3 , ZrO 2 , Al 2 O 3 and SnO 2 as shell materials, we find that the mechanism by which the shell affects the electrode properties depends on the coating material. In the exceptional case of Nb 2 O 5 , the coating forms a surface energy barrier, which slows the recombination reactions. The other shell materials each form a surface dipole layer that shifts the conduction band potential of the core TiO 2 . The shift direction and magnitude depend on the dipole parameters which are induced by the properties of the two materials at the core-shell interface. The results show that either the shell acidity or the electron affinity of the shell are the shift controlling parameters, although the former seems more likely. This new tool for the modification of the electronic properties of the nanoporous electrodes allows for optimization towards a wide range of applications.