Chapter 15
Yet to Be Challenged: TiO 2
as the Photo-Anode Material
in Dye-Sensitized Solar Cells
Janethri B. Liyanage, Ishanie Rangeeka Perera and R. J. K. U. Ranatunga
Abstract Utilization of renewable sources can reduce the impact of increasing
global energy demand on the rate of depletion of fossil fuels. One of the most studied and implemented routes to meet this energy demand is to harvest solar energy.
Among solar-energy harvesting devices, dye-sensitized solar cells have been recognized as some of the cheapest and most environment friendly technologies, since they
do not require high purity of starting materials or advanced fabrication techniques.
A dye-sensitized solar cell is composed of a working electrode, in which the light
absorbing sensitizer is chemisorbed onto the surface of a wide bandgap semiconductor; a redox electrolyte, that is placed in between two electrodes and functions to
regenerate the sensitizer; and a counter electrode, which is a catalyst which accelerates a redox reaction with the electrolyte. Titanium dioxide (anatase phase) is the
most widely used semiconductor material in dye-sensitized solar cells due to its
low cost, chemical stability and optical properties. In this chapter, the literature on
optimizing TiO 2 as a semiconductor material for n-type DSCs is reviewed. The evolution of TiO 2 nanostructures and techniques such as doping, composite preparation
and surface modification are elaborated on. These methods have enhanced both the
chemical and physical properties of TiO 2 nanostructures. Moreover, despite good
overall performance, rapid recombination kinetics are a major disadvantage inherent
in TiO 2 . Thus, research has been carried out to substitute TiO 2 with alternative semiconductors. In view of this, other potential competitors for photo-anode material are
reviewed and assessed. Finally, the prospects of an ideal semiconductor material for
dye-sensitized solar cells is discussed.
J. B. Liyanage · I. R. Perera (B) · R. J. K. U. Ranatunga (B)
Department of Chemistry, University of Peradeniya, Peradeniya 20400, Sri Lanka
e-mail: ishanieperera@pdn.ac.lk
R. J. K. U. Ranatunga
e-mail: udyranatunga@pdn.ac.lk
J. B. Liyanage
e-mail: janethriliyanage@gmail.com
I. R. Perera · R. J. K. U. Ranatunga
Postgraduate Institute of Science, University of Peradeniya, Peradeniya 20400, Sri Lanka
© Springer Nature Singapore Pte Ltd. 2020
H. Tyagi et al. (eds.), Solar Energy, Energy, Environment,
and Sustainability, https://doi.org/10.1007/978-981-15-0675-8_15
285
Yet to Be Challenged: TiO 2
as the Photo-Anode Material
in Dye-Sensitized Solar Cells
Janethri B. Liyanage, Ishanie Rangeeka Perera and R. J. K. U. Ranatunga
Abstract Utilization of renewable sources can reduce the impact of increasing
global energy demand on the rate of depletion of fossil fuels. One of the most studied and implemented routes to meet this energy demand is to harvest solar energy.
Among solar-energy harvesting devices, dye-sensitized solar cells have been recognized as some of the cheapest and most environment friendly technologies, since they
do not require high purity of starting materials or advanced fabrication techniques.
A dye-sensitized solar cell is composed of a working electrode, in which the light
absorbing sensitizer is chemisorbed onto the surface of a wide bandgap semiconductor; a redox electrolyte, that is placed in between two electrodes and functions to
regenerate the sensitizer; and a counter electrode, which is a catalyst which accelerates a redox reaction with the electrolyte. Titanium dioxide (anatase phase) is the
most widely used semiconductor material in dye-sensitized solar cells due to its
low cost, chemical stability and optical properties. In this chapter, the literature on
optimizing TiO 2 as a semiconductor material for n-type DSCs is reviewed. The evolution of TiO 2 nanostructures and techniques such as doping, composite preparation
and surface modification are elaborated on. These methods have enhanced both the
chemical and physical properties of TiO 2 nanostructures. Moreover, despite good
overall performance, rapid recombination kinetics are a major disadvantage inherent
in TiO 2 . Thus, research has been carried out to substitute TiO 2 with alternative semiconductors. In view of this, other potential competitors for photo-anode material are
reviewed and assessed. Finally, the prospects of an ideal semiconductor material for
dye-sensitized solar cells is discussed.
J. B. Liyanage · I. R. Perera (B) · R. J. K. U. Ranatunga (B)
Department of Chemistry, University of Peradeniya, Peradeniya 20400, Sri Lanka
e-mail: ishanieperera@pdn.ac.lk
R. J. K. U. Ranatunga
e-mail: udyranatunga@pdn.ac.lk
J. B. Liyanage
e-mail: janethriliyanage@gmail.com
I. R. Perera · R. J. K. U. Ranatunga
Postgraduate Institute of Science, University of Peradeniya, Peradeniya 20400, Sri Lanka
© Springer Nature Singapore Pte Ltd. 2020
H. Tyagi et al. (eds.), Solar Energy, Energy, Environment,
and Sustainability, https://doi.org/10.1007/978-981-15-0675-8_15
285