Science News : 2021 Nature, R.H. Friend, Over 20% OPV Design

　　Nature (IF 49.962) recently reported that by optimizing the structure of non-fullerene acceptors (NFA), organic solar cells can have 20% or higher power conversion efficiency (PCE).

　　The use of non-fullerene acceptors (NFA) in organic solar cells can improve the efficiency of organic solar cells, but its efficiency is still lower than that of inorganic solar cells (the power conversion efficiency is usually more than 20%). The key factor is the low open circuit voltage of organic solar cells.

　　In order to compete with inorganic solar cells in terms of efficiency, we must determine and suppress non-radiation loss paths of organic solar cells . In this study, the authors used engineering substantial hybridization to reorganize the non-radiative channel and studied it through a solar simulator. The results showed that the reverse charge conversion rate may be reduced by an order of magnitude, and the spin-triplet charge-transfer excitons can be re-dissociated. The authors also demonstrated the NFA system, showing that the formation of triplet excitons was suppressed. Therefore, this research provides a design approach for organic solar cells with over 20% power conversion efficiency (PCE).

　　In scientific research, the quantum efficiency measurement system is also used to analyze the EQE (External Quantum Efficiency) spectra of solar cells. At the same time, it also provides the ratio of Jsc (short-circuit current density) for the short-circuit current of solar cells under the solar simulator to prove the authenticity of the experiment. Furthermore, Enlitech’s solar simulator of and the KA-6000 software provide monitoring of the short-circuit current over time to prove the stability of the solar cell!