1. Solar Energy: Organic Photovoltaics Courtney Klosterman Case Western Reserve University Physics Department REU Summer Program

2. Outline of Presentation Big Picture Problem Background: Silicon/Organic Solar Cells What I’m looking at: Structures and Calculations Goal Matching Calculations Future Work

4. Prevents their widespread use to generate electricity

5. Most solar cells today are made of silicon in different states: crystalline, multicrystalline or amorphoushttp://www.devicedaily.com

7. Recombination at the junction creates a depletion region with a large built-in electric field

9. The polymers poly-3-hexylthiophene (P3HT) and Phenyl-C61-butyric acid methyl ester (PCBM) are mixed together to form an interpenetrating network of p and n type material called a bulk heterojunction. http://www.livescience.com http://riekemetals.thomasnet.com http://www.phys.tue.

11. When the exciton reaches an interface between the p and n-type materials, charge is transferred which breaks the exciton and allows charge to be extracted to the electrodes.

14. The absorption peak would be optimized around 50nm layer thickness of the polymer photovoltaic.

15. Similar to a laser cavity effect called frequency pullingITO, PV, Al ITO, PV, no cavity effect

17. How we make slides Use commercial ITO glass, or Sputter-coat ITO Mix Polymers together, dissolve well Spin coat polymers at various speeds Evaporate Aluminum or Sputter-coat Silver Sputter-coater Some finished Samples Evaporator

23. More structures with Bilayer

24. Look at electrical properties

25. Find parameters that give good absorption and electrical propertiesGlove Box System at Ohio State Organic Solar Cell IV Curve http://deibel.files.wordpress.com

26. Acknowledgements Kenneth D. Singer Brent Valle National Science Foundation Clips/SOURCE QUESTIONS?