Dye-sensitized Solar Cells (DSC)
Solar energy can be converted to electricity by
amorphous or crystalline silicon
photovoltaic cells. An
alternative low cost technology for the conversion of Solar energy is the Dye-sensitized Solar Cell (DSC).
DSCs
are made under ambient conditions by chemical processes and, for this reason, the cost of their production
is very low. In addition, DSCs are semi-transparent, they can receive
light, practically, at any angle and in any direction and they can be used as
photovoltaic windows either in buildings or in small devices. Low cost, easy fabrication and transparency
make them competitive against the existing silicon photovoltaics technology. The following diagram shows the basic
function of a DSC.
The function of a DSC. Nanocrystalline titania is deposited on a transparent electrode while a
sensitizer is in intimate contact with the semiconductor nanoparticles. The
excited state of the sensitizer must lie higher (i.e. be more electronegative)
than the conduction band of the semiconductor.
Light is absorbed by the sensitizer.
The excited electron is injected
into the conduction band of the semiconductor and is driven by means of an
external circuit towards the cathode, usually made also of a transparent electrode
bearing a thin layer of Pt electrocatalyst.
The electrocatalyst facilitates electron transfer from the electrode to
the redox electrolyte (I3-/I-). The electrolyte facilitates charge transport
and neutralization of the hole left in the excited sensitizer so that the cell
works in a cyclic manner. The
open-circuit voltage Voc is determined by combination of the Fermi
level of the semiconductor and the redox level of the electrolyte.
A solid type DSC, based on nanocomposite organic-inorganic
materials, has been developed in our
laboratory and it is described below by
the diagram showing a cross section of the cell.
The cell consists of two transparent electroconductive glass SnO2:F commercial electrodes. On the lower electrode (negative
electrode), a thin (2mm) transparent
nanocrystalline TiO2 film is deposited as a nanocomposite
organic-inorganic material made by the sol-gel method, subsequently calcined at high
temperature. A dye sensitizer is then
adsorbed and chemically anchored on
titania. The second electrode
(positive electrode) is slightly platinized. Between the two electrodes there
is a solid gel supporting an electrolyte
also made by the sol-gel method.
Related Publications
1. Dye-sensitized
photoelectrochemical cell using a nanocomposite
SiO2/poly(ethylene glycol) thin film as electrolyte support. Characterization by time-resolved
luminescence and conductivity measurements.: E.
Stathatos, P.Lianos and Ch.Krontiras, J.Phys.Chem Β. 105(2001)3486-3492.
2. Structural Study of Hybrid Organic/inorganic Polymer
Gels by using Time-Resolved Fluorescence Probing : E. Stathatos, P.Lianos, U.Lavrencic Stangar, B.Orel and P.Judeinstein, Langmuir,
16(2000)8672-8676.
3. Synthesis of a hemicyanine
dye bearing two carboxylic groups and its use as photosensitizer in
Dye-Sensitized Photoelectrochemical Cell: E.
Stathatos, P.Lianos, A.Laschewsky, O.Ouari and P. Van Cleuvenbergen, Chem.Mater., 13(2001)3888-3892.
4. Organic/inorganic nanocomposite gels employed as electrolyte supports in Dye-sensitized Photoelectrochemical cells: E.Stathatos and P.Lianos, Intern.J.Photoenergy, 4(2002)11-16.
5. A sol-gel type electrolyte for a dye-sensitized
solar cell: Attenuated total reflectance
(ATR) vibrational spectra studies: U.Lavrencic Stangar,
B.Orel,
B.Neumann, E.Stathatos
and P.Lianos, J.Sol-gel Sci.Techn., 26(2003)1113-1118.
6. In situ resonance Raman microspectroscopy
of a solid state dye-sensitized photoelectrochemical
cell: U.Lavrencic Stangar, B.Orel, Ph.Colomban, E.Stathatos and P.Lianos, J.Electrochem.Soc., 149(2002)E413-E423.
7. In situ resonance Raman studies of a dye-sensitized photoelectrochemical cell with a sol-gel electrolyte: U.Lavrencic Stangar,
B.Orel,
N.Groselj, Ph.Colomban,
E.Stathatos and P.Lianos, J.New Mater.Electrochemical Systems, 5(2002)223-231.
8. A high performance solid state Dye-sensitized
Photoelectrochemical Cell employing a nanocomposite
gel electrolyte made by the sol-gel route : E.Stathatos,
P.Lianos, U.Lavrencic Stangar and B.Orel, Advanced
Materials, 14(2002)354-357.
9. A Nanocomposite Gel Electrolyte Made by the Sol-Gel Route for
a Solid-State Dye-Sensitized Photoelectrochemical and Electrochromic
Cells: Boris
Orel, Urska Lavrencic Stangar, Angela Surca Vuk, Panagiotis Lianos,
Philippe Colomban,
Materials Research Society Symposium Proceedings 725(2002)P7.3.1-P7.3.6.
10. Development
of sol-gel redox I3-/I- electrolytes and their applications in
hybrid electrochromic devices: B.Orel, A.Surca-Vuk, R.Jese, P.Lianos, E.Stathatos, P.Judeinstein, Ph.Colomban, Solid State Ionics,
165(2003)235-246.
11. A quasi-solid-state
dye-sensitized solar cell based on a sol-gel nanocomposite
electrolyte containing ionic liquid: E.Stathatos, P.Lianos, S.M.Zakeeruddin, P. Liska and M.Grätzel, Chem.Mater., 15(2003)1825.
12. Study of acetic-acid-catalyzed nanocomposite
organic/inorganic ureasil sol-gel ionic conductors: E.Stathatos, P.Lianos,
B. Orel, A. Surca Vuk, R. Jese, Langmuir,
19(2003)7587-7591.
13. Optimization of quasi-solid state dye-sensitized photoelectrochemical
solar cell employing a ureasil/sulfolane gel
electrolyte: E.Stathatos, P.Lianos, A . Surca Vuk and B. Orel, Advanced Functional Materials, 14(2004)45-48.
14. Highly Efficient
Nanocrystalline Titania Films made from Organic/Inorganic Nanocomposite
Gels: E.Stathatos, P.Lianos and C.Tsakiroglou, Microporous.-Mesoporous
Materials, 75(2004)255-260.
15. Dye-sensitized photoelectrochemical
solar cells based on nanocomposite organic-inorganic materials: Elias Stathatos, Panagiotis
Lianos, Vasko Jovanovski and Boris Orel, J.Photochem.Photobiol.
A. Chemistry 169 (2005) 57-61
16. Dye-sensitized
solar cells with electrolyte based on a trimethoxysilane
derivatized ionic liquid: Vasko Jovanovski, Elias Stathatos, Boris
Orel, Panagiotis Lianos, Thin Solid Films
511-512(2006)634-637.
17. A Novel
Polysilsesquioxane-I2/I3- ionic electrolyte
for dye-sensitized photoelectrochemical
cells: Vasko Jovanovski, Boris Orel, Robi Jese, Angela
Surca Vuk, Gregor Mali, Joze Grdadolnik, Adolf Jesih, Elias Stathatos and Panagiotis Lianos, J.Phys.Chem. Β,
109(2005)14387-14395.
18. Positevely charged polysilsesquioxane/iodide ionic
liquid as a quasi solid state redox electrolyte for dye-sensitized photoelectrochemical solar cells : Infrared, 29Si
NMR and
electrical studies: Vasko Jovanovski, Boris Orel, Robi Jese, Gregor
Mali, Elias Stathatos and Panagiotis
Lianos, J.Photoenergy (2006)1-8.
19. Dye-sensitized solar cells
based on nanocrystalline titania electrodes made at various sintering temperatures :
Elias Stathatos
and Panagiotis
Lianos, J.Nanoscience
and Nanotechnology, 7(2007)555-559.
20. Dye-sensitized
solar cells made by using a polysilsesquioxane
polymeric ionic fluid as redox electrolyte: Elias Stathatos, Vasko Jovanovski, Boris
Orel,
Ivan Jerman and Panagiotis Lianos, J.Phys.Chem. C, 111(2007)6528-6532.
21. Solid-state
Dye-sensitized Solar Cells made of multilayer nanocrystalline
Titania and Poly(3-hexylthiophene): Nikolaos Balis, Vassilios Dracopoulos, Maria Antoniadou and Panagiotis Lianos, J.Photochem.Photobiol. A:
Chemistry, 214(2010)69-73.
22. Study of hybrid
solar cells made of multilayer nanocrystalline
titania and poly(3-octylthiophene) or poly-(3-(2-methylhex-2-yl)-oxy-carbonyldithiophene): Maria Antoniadou, Elias Stathatos, Nikolaos Boukos, Andreas Stefopoulos, Joannis Kallitsis, Frederik C.
Krebs and Panagiotis Lianos,
Nanotechnology 20(2009) Art.No.495201
23. Cost-effective dye-sensitized solar cells based on
commercial nanocrystalline titania
and a ureasil gel electrolyte: Maria Antoniadou
and Panagiotis Lianos, European
Physics Journal-Applied Physics, in press.