Density Functional Theory Studies of
Ruthenium Dye (N3) Adsorbed on a TiO 2
Brookite Cluster for Application in Dye
Sensitized Solar Cells
I. F. Elegbeleye, N. E. Maluta and R. R. Maphanga
Abstract Titanium dioxide has been a subject of increasing interest due to its
application in pigments, photocatalysis and semiconductor materials in dye sensitized solar cells (DSSC). Recent studies suggest that TiO 2 brookite exhibits good
photocatalytic properties. Efficiency in excess of 11% has been achieved with the
use of ruthenium (N3) dyes as DSSC sensitizer. The optical properties, energy level
alignment and electronic state energy of the ruthenium (N3) sensitizer to TiO 2 cluster
were studied to gain insight into the electron injection kinetics and electron injection
efficiency of the dye/TiO 2 complex. The simulated absorption spectra show absorption peaks at 311, 388 and 480 nm. The HOMO of (N3) lies at −5.03 eV and is
centred on the NCS moiety where the donor group is situated, while the LUMO lies
at −3.01 eV and is centred on the 4,4-dicarboxy-2,2-bipyridine moiety where the
acceptor group is situated. Upon absorption on a brookite cluster, the light absorption maximum red shifted to higher wavelength; this results in the distribution of
the LUMO shifting from the dye to the TiO 2 cluster. The results suggest favourable
electron injection from the dye excited state into TiO 2 semiconductor. The results
suggest that TiO 2 brookite is a promising entrant for DSSC semiconductor.
Keywords Density functional theory · Dye sensitized solar cell · Ruthenium dye ·
Red shift on cluster formation · TiO 2 brookite
1 Introduction
In recent years, TiO 2 has been a subject of increasing interest due to its applications
in pigments, photocatalysis and semiconductor materials in dye sensitized solar cells
I. F. Elegbeleye · N. E. Maluta
Department of Physics, University of Venda, Thohoyandou, South Africa
N. E. Maluta (B) · R. R. Maphanga
National Institute for Theoretical Physics (NITheP), Gauteng, South Africa
e-mail: Eric.Maluta@univen.ac.za
R. R. Maphanga
Council for Science and Industrial Research, P.O. Box 395, Pretoria, South Africa
© Springer Nature Switzerland AG 2020
L. Mammino et al. (eds.), Advances in Quantum Systems in Chemistry,
Physics, and Biology, Progress in Theoretical Chemistry and Physics 32,
https://doi.org/10.1007/978-3-030-34941-7_8
143
Ruthenium Dye (N3) Adsorbed on a TiO 2
Brookite Cluster for Application in Dye
Sensitized Solar Cells
I. F. Elegbeleye, N. E. Maluta and R. R. Maphanga
Abstract Titanium dioxide has been a subject of increasing interest due to its
application in pigments, photocatalysis and semiconductor materials in dye sensitized solar cells (DSSC). Recent studies suggest that TiO 2 brookite exhibits good
photocatalytic properties. Efficiency in excess of 11% has been achieved with the
use of ruthenium (N3) dyes as DSSC sensitizer. The optical properties, energy level
alignment and electronic state energy of the ruthenium (N3) sensitizer to TiO 2 cluster
were studied to gain insight into the electron injection kinetics and electron injection
efficiency of the dye/TiO 2 complex. The simulated absorption spectra show absorption peaks at 311, 388 and 480 nm. The HOMO of (N3) lies at −5.03 eV and is
centred on the NCS moiety where the donor group is situated, while the LUMO lies
at −3.01 eV and is centred on the 4,4-dicarboxy-2,2-bipyridine moiety where the
acceptor group is situated. Upon absorption on a brookite cluster, the light absorption maximum red shifted to higher wavelength; this results in the distribution of
the LUMO shifting from the dye to the TiO 2 cluster. The results suggest favourable
electron injection from the dye excited state into TiO 2 semiconductor. The results
suggest that TiO 2 brookite is a promising entrant for DSSC semiconductor.
Keywords Density functional theory · Dye sensitized solar cell · Ruthenium dye ·
Red shift on cluster formation · TiO 2 brookite
1 Introduction
In recent years, TiO 2 has been a subject of increasing interest due to its applications
in pigments, photocatalysis and semiconductor materials in dye sensitized solar cells
I. F. Elegbeleye · N. E. Maluta
Department of Physics, University of Venda, Thohoyandou, South Africa
N. E. Maluta (B) · R. R. Maphanga
National Institute for Theoretical Physics (NITheP), Gauteng, South Africa
e-mail: Eric.Maluta@univen.ac.za
R. R. Maphanga
Council for Science and Industrial Research, P.O. Box 395, Pretoria, South Africa
© Springer Nature Switzerland AG 2020
L. Mammino et al. (eds.), Advances in Quantum Systems in Chemistry,
Physics, and Biology, Progress in Theoretical Chemistry and Physics 32,
https://doi.org/10.1007/978-3-030-34941-7_8
143