1. Combined experimental and theoretical investigation of the hemi-squaraine/TiO2 interface for dye sensitized solar cells
- Author
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Andrea Lamberti, Elena Maria Tresso, Adriano Sacco, Diego Pugliese, Giuseppe Caputo, Bruno Camino, Claudia Barolo, Nadia Shahzad, Barbara Ballarin, Anna Maria Ferrari, Giancarlo Cicero, Francesca Risplendi, Giorgia Musso, Stefano Bianco, Giancarlo Cicero, Giorgia Musso, Andrea Lamberti, Bruno Camino, Stefano Bianco, Diego Pugliese, Francesca Risplendi, Adriano Sacco, Nadia Shahzad, Anna Maria Ferrari, Barbara Ballarin, Claudia Barolo, Elena Tresso, and Giuseppe Caputobc
- Subjects
SOLAR CELLS ,General Physics and Astronomy ,Squaric acid ,Photochemistry ,Isonicotinic acid ,DYE-SENSITIZED SOLAR-CELLS ,chemistry.chemical_compound ,Dye-sensitized solar cell ,Electron transfer ,hemi-squaraine ,chemistry ,Ab initio quantum chemistry methods ,Moiety ,Molecule ,Density functional theory ,titania ,Physical and Theoretical Chemistry ,DYES - Abstract
A simple hemi-squaraine dye (CT1) has been studied as a TiO2 sensitizer for application in dye sensitized solar cells (DSCs) by means of a combined experimental and theoretical investigation. This molecule is a prototype dye presenting an innovative anchoring group: the squaric acid moiety. Ab initio calculations based on Density Functional Theory (DFT) predict that this acid spontaneously deprotonates at the anatase (101) surface forming chemical bonds that are stronger than the ones formed by other linkers (e.g. cathecol and isonicotinic acid). Moreover an analysis of the electronic structure of the hybrid interface reveals the formation of a type II heterostructure ensuring adiabatic electron transfer from the molecule to the oxide. DSCs containing hemi-squaraine dyes were assembled, characterized and their performances compared to state of the art cells. Experimental results (large incident photon-to-electron conversion efficiency and an efficiency of 3.54%) confirmed the theoretical prediction that even a simple hemi-squaraine is an effective sensitizer for TiO2. Our study paves the way to the design of more efficient sensitizers based on a squaric acid linker and specifically engineered to absorb light in a larger part of the visible range.
- Published
- 2013