By Dr. Cameron Chai
Researchers from the U.S. Department of Energy's (DOE) Brookhaven National Laboratory have performed a study on an organic photovoltaic material with superior performance and showed that the PV material performed better due to the presence of an uncommon bilayer lamellar structure.
The study was performed in association with the Max Planck Institute for Polymer Research, Germany, Seoul National University, Korea, Konarka Technologies and Stony Brook University.
This material also called PCDTBT, being an example of a polycarbazole conjugated polymer, which is a molecule comprising alkyl side chains linked to a chainlike carbon backbone. Its capability in donating and accepting electrons makes it a superior performer and helps it convert at a high efficiency up to 7.2%.
The study was conducted at the Brookhaven's National Synchrotron Light Source. Using a high-resolution x-ray scattering method, thin films of PCDTBT were exposed to strong x-ray beams. At high temperatures, a crystalline-like phase was formed. This formation was not observed in earlier studies, which used x-rays with less intensity. In addition, the x-ray patterns revealed a structure containing conjugated backbone pair layers, whereas, other organic solar cells, studied till date, contain only single backbone layers.
Benjamin Ocko, a physicist at Brookhaven and head for the current study, stated that in- depth studies have been performed on the polymer, however, the researchers did not focus on the structural characteristics of the polymer that rendered better performance. He added that knowing the reason for the better performance of the material will facilitate the researchers to develop novel materials for a broad range of uses, which include enhanced PVs, transistors, displays and solid-state lighting.
The paper has been published in the journal, Nature Communications.