Towards an all-solution processed polymer solar cell

摘要

To reduce the costs of polymer solar cells it is important to develop a fully solution processed route. Althoughseveral successful generic routes to solution processed hole collecting electrodes have been shown, this is not the casefor the electron collecting electrode of polymers cells, as it is hard to find a solution processable low workfunction,low ohmic, electron collecting electrode. Here an efficient recombination layer is described formed by thecombination of ZnO and PEDOT and applied in an electron collecting layer. The ZnO contacts the conduction bandof the acceptor material to collect electrons from the absorber layer. Since ZnO is a wide bandgap material, it alsoacts as an exciton and hole blocking layer. Electrons collected by the ZnO layer easily recombine with holes from thehighly doped, high conductive PEDOT layer. The performance of a device with a recombination layer is compared ina standard as well as inverted polymer solar cells. The performance of the device with the PEDOT/ZnOrecombination layer deviates less than 10 % from similarly processed standard and inverted device structures.