HOPV12 - Blogs

4 th Hybrid and Organic Photovoltaic Conference -Uppsala 2012 230
C101 - Search for Dye Sensitized Solar Cell High Efficiency Organic Cromophore Loci
Mihai Mihaila, Cristian Diaconu, Octavian Buiu, Bogdan Serban, Viorel Avramescu
Honeywell Romania, ACS Sensors and Wireless Laboratory – Bucharest, Floreasca str. 161B, Sector 1, 014459, Bucharest, Romania,
RO
In this work, we investigate how the efficiency of the organic dye-based DSSCs distributes
into the plane having the absolute electronegativity (χ) [1] and the global hardness (η) [2] of
the cromophore as coordinates. To this purpose, experimental HOMO/LUMO values of 133
organic cromophores were collected from literature [3]-[38] and their χ[1] and η[2] were
calculated assuming the validity of the Koopman’s theorem *39+.
Fig. 1 shows the distribution of the efficiency (y) in the (χ,η) plane. For χ1.083eV were found.
These molecules cannot easily attract electrons from the TiO2 conduction band and,
consequently, the dominant recombination mechanism in these cells could be the electron
interception by electrolyte. As Fig. 1 shows, neither harder (high η) nor softer (low η)
cromophores are very efficient. On the hardness scale, except for three cromophores, the
locus of the most efficient (y>6.75%) ones is defined by 1.1eV