Interesting Structure Found in Organic Solar Panel
Solar power is being intensely studied across the planet as researchers try to find ways to make it more efficient and less expensive. One way to make it less expensive is to use organic materials instead of silicon or other semiconductors. A large reason for why the organic solar panels can be less expensive is because they can be reduced using a printing method similar to how newspapers are printed. Researchers at the DOE's Brookhaven National Laboratory (BNL), in collaboration with Stony Brook University, Seoul National University in Korea, the Max Planck Institute for Polymer Research in Germany, and Konarka Technologies, have closely examined PCDTBT, the most efficient organic solar cell material, and found what causes its high 7.2% efficiency.
Though the material has been intensely studied for quite a while, researchers had not previously looked too closely at its crystalline structure. Those at BNL though have the ability to use a high-resolution x-ray scattering technique and decided to see what is going on beneath PCDTBT’s surface.
It turns out PCDTBT has a double backbone structure, which differs from every other organic solar material. These other materials only have one backbone, which carries the electrical current through the material. Also, along the backbones of organic solar materials are other molecules, alkyl in the case of PCDTBT. These molecules can interfere with the electrical properties of the backbone, but there are fewer of these chains in PCDTBT.
Now that the researchers understand why PCDTBT has such high efficiency, it should be possible to enhance that material or create new polymers with even higher efficiencies.