Organic photovoltaic (OPV) cells are a new type of solar cell, with organic materials as the main component, hence the name “organic photovoltaics.” They are lighter and cheaper than traditional solar cells and can be printed into larger areas, making them more efficient and flexible. However, the efficiency of OPV cells is still relatively low, and efficient photon utilization is crucial for achieving high-performance organic photovoltaics.

      A research was published in Advanced Materials in January 2023, where Jianhui Hou’s team improved the performance of organic photovoltaic (OPV) cells by using effective photon collection. By regulating donor and acceptor phase transition kinetics, they constructed a multiscale fibril network morphology in a PBQx-TCl:PBDB-TF:eC9-2Cl-based system. Compared to binary systems, the ideal multiscale primary fiber network morphologies enable the tri-system to achieve superior charge transfer and transport processes; these improvements promote the increase of photon utilization efficiency. The external quantum efficiency of the optimized tri-cell exceeded 85% within the broad range of 500-800 nm.

       The research team used the SRC-2020 standard cell and QE-R quantum efficiency measurement system of Enlitech. The results achieved power conversion efficiency of up to 19.51% for both single junction and string OPV cells, and PCE exceeding 20%. This research provides insight into improving the photon collection efficiency of OPV cells through ideal multiscale primary fiber network morphologies.