• Rantala, Tapio T.
• Kontkanen, Outi V.
• Hukka, Terttu

Abstract

<p>In this paper, we investigate the electronic structures of triphenylamine molecules with three different anchoring groups (pyridinyl, carboxyl, and phenyl-1,2-diol) before and after attachment with a p-type semiconductor, nickel oxide (100), surface. To understand the charge transfer characteristics of these structures commonly used in dyes of the dye-sensitized solar cells (DSSC), we use periodic models to study their configurations with density functional theory (DFT). We find that carboxyl and phenyl-1,2-diol anchors adsorb more strongly compared to pyridinyl anchor on NiO(100). Stronger binding is reflected as a bigger dipole moment and a more viable charge transfer from the anchors to NiO(100). Furthermore, the alignment of electronic levels favors charge transfer only for pyridinyl and phenyl-1,2-diol anchors. Despite its weaker binding on the NiO(100) surface, pyridinyl is a more promising anchoring group for transferring charge to NiO, as it does not create trap states.</p>

Topics

• density
• impedance spectroscopy
• surface
• nickel
• theory
• density functional theory
• p-type semiconductor