A new polymer film could enhance the light harvesting properties and hence the efficiency of organic solar cells. The material developed by Riken, a Japanese research institute, has a “polymer brush”-like structure, with a main chain densely branches into long side chains.
By embedding Azobenzene molecules, the researchers turned the material into a film. Azobenzene molecules have a structure in which two benzene rings are connected by two nitrogen atoms. Light and heat were found to affect the material’s structure with a reversible effect.
The Japanese have been tinkering with azobenzene molecules in the past, making light-sensitive motors.
The material discovered by Riken could be used to manufacture artificial muscles and could also play a role in organic solar cells, by enabling functional molecules to carry electrons from the top side of an organic solar cell to its back side, increasing the film’s efficiency.