By Kelen Tuttle, Stanford Synchrontron Radiation Lightsource
Solar power is an important component of our society’s future energy portfolio, and organic materials may be the technology that makes solar cells cheap enough for wide-spread implementation.
Currently, organic or plastic solar cells are relatively inexpensive to make, yet they are also relatively inefficient. Researchers from Princeton University and SSRL recently studied the structure of organic solar cells that were manufactured and processed in different ways to better understand the causes of the inefficiencies.
The experiments, conducted at SSRL Beam Line 11-3, showed a complex relationship between the crystallinity of an organic solar cell’s active layer and the cell’s output current. Output currents were not directly tied with the crystallinity of the polymer (P3HT) in the active layer, as was expected. Instead, the researchers found that the output currents were correlated with the polymer crystallinity only in solar cells in which the fullerene derivative (PCBM), also contained in the active layer, was locally well organized. These results show that the structure of both components is very important, and should both be considered to increase organic solar cell performance. This work was published in the January 7, 2011, issue of Chemical Communications.
Gomez, E. D., Barteau, K. P., Wang, H., Toney, M. F. & Loo, Y.-L. Correlating the scattered intensities of P3HT and PCBM to the current densities of polymer solar cells. Chemical Communications 47, 436-438 (2011).
Enrique D. Gomez