Dr. Chris Collison, assistant professor of chemistry, and his chemistry research group have developed a model that quantitatively describes comparisons of polymer materials used as dispersants for carbon nanotubes in organic solvents. The e!ort, funded by the American Chemical Society, has gained international recognition at a host of conferences and peer-reviewed journals, including the Journal of Physical Chemistry B and C.
With better polymer dispersants, carbon nanotubes are being utilized for "exible transparent electrodes in emerging photovoltaic devices. Collison, who also serves as the group leader of RIT's Nanopower Research Laboratories' Polymer Photovoltaics group, is developing a tandem layer organic solar cell. Each active layer in the cell converts a different region of the solar spectrum to electricity. These devices will yield low-cost, "exible, and aesthetically pleasing solar cells that are well targeted for consumer electronics.
In organic photovoltaics light is absorbed by an organic material, which is chemically tailored to optimize the device. The excited state that is created migrates to an interface with a second organic "electron acceptor." The resulting electron and hole, now "free," can di!use through the organics and the electron and hole are captured at two electrodes.
The mechanism for this process is hotly debated and has significant research underway to improve the process. RIT's Polymer Photovoltaics group is one of five international groups making strides with a set of squaraine molecules, which absorb strongly in the near infrared and show immense promise for stable, solution-cast films, vital for low-cost manufacture. The group is also studying the e!ective dispersion of carbon nanotubes for the spray coating of more sustainable transparent electrodes.