Researchers at the Chinese Academy of Sciences claim to have demonstrated a conversion efficiency of 17% in an organic PV cell with a small area of 0.09 cm2.
The cell is based on a new non-fullerene electron acceptor, which is said to be a new class of the Y6 non-fullerene acceptor that is widely used in research on organic solar cells.
The scientists developed the new BTP-4Cl-12 acceptor by optimizing the alkyl chains of BTP-4Cl, which is a derivative of the well-known Y6.
By using a blade-coating method, the scientists expanded the active area of the cell to 1.0 cm2 at a later stage. The device efficiency declined by 1.5%, which the researchers claim is still a very good level.
They also described the new acceptor as having balanced solution processability and aggregation features. “The blade-coating film showed a very good phase separation morphology, which contributed to the high carrier transport and suppressed charge recombination in the OPV cells,” the research team stated.
The paper, 17% efficiency organic photovoltaic cell with superior processability, was published in the National Science Review. It notes that the new non-fullerene acceptor has a suitable solubility and thus a desirable morphology.
The scientist found that the efficiency of the demonstrated spin-coated OPV devices can also be maintained with the presented scalable blade-coating processing technology.