Organic Solar Cells: The Technology and the Future Diana Snelling 11-19-07 ChE 384

Performance Comparison Lawrence Kazmerski, Don Gwinner, Al Hicks, 11/7/07, United States Department of Energy. Best Research-Cell Efficiencies.

Traditional Cells vs. Organic 100nm 100 nm 100 nm Bulk Heterojunction Benanti, Travis L, and D Venkataraman. "Organic solar cells: An overview focusing on active layer morphology." Photosynthesis Research 87 (Apr. 2005): 73-81.

Organic Semiconductors Chemistry of polymers is well understood Chemically tunable Band gap Valence and conduction energies Charge transport Solubility Structural properties The variety of organic materials that can be synthesized greatly overwhelms the variety of inorganic materials possible

Organic Materials for PV Intrinsic property: donor or acceptor Extrinisic property: p or n doped by impurities Kinetic property: efficient electron or hole transport determined by orbital overlap a – c are good donors d & f are good acceptors

Organic Cell Structure J.-M. Nunzi. “Organic photovoltaic materials and devices.” C. R. Physique 3 (2002): 523-542.

Advantages and Challenges Inexpensive Lightweight Disposable Flexible Environmental Niche applications Efficiency Degradation Competition with existing Si industry Power farms

Conclusions Great research opportunity POTENTIAL Applications Cost Organic solar cells are probably not a solution for our large-scale future energy problems