IntroductionDye Solar Cells• Low cost thin film solar cells• Invented by Michael Grätzel in 1991• Mechanically robust and can be made on flexible sheets• Commercialization just started with three major companies: DyeSol, Austraila; Solaronix, France; ECIC, Taiwan.
Construction & Working:
Advantages:• Works well under diffused sunlight, less sensitive to angle of incidence.• Can be made fully transparent, can have a lot of aesthetic applications.• Bifacial, absorbs light from both faces, can be inverted.• Manufacturing costs much cheaper than the commercially available PV silicon cells.• Also works at high temperature, owing to the thin conducting film that radiates internal heat.
Materials & Methods:DSC’s four major components:1. Conducting glass2. TiO2 layer3. Dye4. Electrolyte5. Counter electrode
Building of DSC:Conducting glass:• Commercially available as ITO (Indium Tin oxide glass) used normally in LCD screens.• Glass with a resistance of at least 30Ω/sq.cm is required.• Glass has to be highly transparent.• A normal 160 * 80 mm ITO glass (4mm thick) costs around $150 (Courtesy: Dyesol Inc.)
Lab preparation of conducting glass •Stannic Chloride is obtained and dissolved in ethanol(40% w/w) solution – (5 gm in 5ml of methanol) •It is sprayed upon the glass surface with the help of a mister. •The glass is then kept in the muffle furnace and is heated up to 400-500 ° C for about 15-20 min •Sn4+ gets reduced to Sn2+, forming a mix layer of SnO2 & SnO4, which are responsible for conductivity
Conducting glass by Thermal Evaporation @IPR, Gandhinagar
Procedure to build a DSC(Materials Required)• 2 transparent conductive glass slides (We used glass slides prepared by Thermal Evaporation technique).• Sticky tape• Ruler and a small knife.• Isopropyl alcohol .• Titanium dioxide (Company: Finar 99.0% pure)• Mortar with pistil• Acetic Acid• Triton X-100 (Surfactant)• Muffle furnace (at least 450°C)• Potassium Iodide crystals• Dye (we used Santalin)• Spirit lamp• Fire tongs• Glass rod
Step by Step process:• Check for conducting side• Preparation of glass slide• TiO2 Coating
Contd..• Heating the coated glass• Preparing the Dye Solution
Contd..• Coating Dye over TiO2• Preparation of Counter electrode
Contd..• Measuring the open-circuit Voltage
ResultsConducting glass Analysis• SEM Analysis
• XRD Analysis Intensity/ cps 2 Theta/ (Scan axis: 2:1 sym.) XRD pattern reveal that films contain SnO and SnO2 both phases with SnO peaks with higher intesities and preferred orientaions.
Transmission Spectra Transm ission Spectra for SnO2 film s deposited by therm al evaporation and Plasm a assisted thermal evaporation 1 250 C 0.8 Transmittance 300 C 0.6 0.4 250 C with RF 0.2 300 C with RF 0 350 415 480 545 610 675 740 805 870 935 1000 Wavelength(nm )Transmission spectra of films show that as the substratetemperature increases transparency of the films increases. Alsospectra of plasma assisted films are lying somewhat above thespectra of thermally grownFilms.
Open Circuit VoltageS. No. Resistivity of Conducting Illumination Voltage(m glass (W/m2) V)1. 89.59 Ω cm 120 (Sun light) 9892. 129.8 Ω cm 120 (Sun light) 6923. 127 Ω cm 120 (Sun light) 4684. 146 Ω cm 250 (Solar Lamp) 19
References• D. Keefer, E. Eibergen, G. Lisensky, J. Tanaka and S. L. Suib, Surface conductive glass, J. Chem. Educ. 61, 1104 (1984).• Beomjin Yoo, Kyungkon Kim, Seung Hoon Lee, Won Mok Kim, Nam-Gyu Park, ITO/ATO/TiO2 triple-layered transparent conducting substrates for dye-sensitized solar cells, Solar Energy Materials & Solar Cells 92 (2008).• Supachai Ngamsinlapasathian, Thammanoon Sreethawong, Doubled layered ITO/SnO2 conducting glass for substrate of dye-sensitized solar cells, Solar Energy Materials & Solar Cells 90 (2006).• B. O’Regan, M. Gratzel, Nature 353, 737 (1991).• B-S. Chiou, J-H. Tsai, J. Mater. Sci. Mater. Electron. 10, 491 (1999).• B.D. Cullity, Elements of X-ray diffraction, Addison-Wesley Publication Company, Reading, MA, 2-9 (1978).• S. Kambe, K. Murakoshi, T. Kitamura, Y. Wada, S. Yanagida, H. Kominami, Y. Kera, Sol. Energy Mater.Sol. Cells 61, 427 (2000).• Haiying Wan, Dye Sensitized Solar Cells, The University of Alabama Publications, 1-13 (2006).• Nazeeruddin, M. K.; Pechy , P.; Grätze, M, Chem. Community, 85 (1997).• M.S. Roy, P. Balraju, G.D. Sharma, Dye-sensitized solar cell based on Rose Bengal dye and nanocrystalline TiO2, Solar Energy Materials & Solar Cells, 1-5 (2007).• A.F. Nogueira, M.A. De Paoli, Sol. Energy Mater. Sol. Cells, 61 (2000).• J.G. Chen, H.Y. Wei, K.C. Ho, Sol. Energy Mater. Sol. Cells, 91 (2007).
Contd…• Yongxiang Li, Dietrich Haarer, Winfried Scharath, Titanium dioxide films for photovoltaic cells derived from a solgel process, Solar Energy Materials and Solar Cells 56, 167-174 (1999) .• K. Tennakone, G.R.R.A. Kumara, I.R.M. Kottegoda, Sensitization of nano-porous films of TiO2 with santalin (red sandalwood pigment) and construction of dye-sensitized solid-state photovoltaic cells, Journal of Photochemistry and Photobiology A: Chemistry 117, 137-142 (1998).• K. Tennakone, G.R.R.A. Kumara, A.R. Kumarasinghe, K.G.U. Wijayantha, P.M. Sirimanna, Semicondutor. Science. Technology 10, 1689 (1995).• Michael Grätzel, Photovoltaic performance and long-term stability of dye-sensitized meosocopic solar cells, C. R. Chimie 9, 578–583 (2006).• Michael Grätzel, Dye Sensitized Solar Cells, Journal of Photochemistry and Photobiology, 2003• Dr. Wolf Peter Stöckl, Research on the usability of low-cost materials in dye sensitized solar cells, HTL Braunau am Inn• http://www.dyesol.com/index.php• http://en.wikipedia.org/wiki/dye_sentisized_solar_cell• http://www.solarprint.ie• http://www.ecic.com/dssc• http://solarcellsinfo.com/blog/archives/category/dye-sensitized-polymer-organic-solar-cells