Low bandgap alternating polyfluorene copolymers in plastic photodiodes and solar cells
- First Online:
- Cite this article as:
- Inganäs, O., Svensson, M., Zhang, F. et al. Appl. Phys. A (2004) 79: 31. doi:10.1007/s00339-003-2498-5
- 586 Downloads
We report a comparative study of plastic photodiodes using four different copolymers of fluorene, with a variation of alkyl side chain length and chemical structure. Photodiode materials are formed by blending the polymers with a fullerene derivative and spincoating the blend solution. A photovoltage of 1 V is obtained in devices, where the anode is a doped polymer and the cathode is LiF/Al. Monochromatic quantum efficiencies are better than 40% over most of the absorption range, and under solar light AM 1.5 simulation, we reach energy efficiencies beyond 2%. The high fill factors obtained in some of the devices indicate that these are of interest for more elaborate optimisation. Reasons for the benign electrical transport are discussed.