Jingchao's work on OPV stability is accepted in Matter

    Polymer solar cells employing polymeric electron donors and acceptors demonstrate superior mechanical property and thermal stability compared to their small molecular counterparts. However, the long-conjugated backbones of polymeric semiconductors are prone to self-entangle into large and disordered aggregates, consequent to inferior PCE as well as quicker degradation during operation.

     Jingchao's recent work found that the incorporation of linearly packed small molecule acceptor can help to disentangle the polymeric chains, transforming the disorder molecular packing into ordered stacking. This simple strategy simultaneously creates efficient pathways for charge transport whilst reducing free volume (i.e. the nanoscopic empty spaces where molecular conformation changes and morphology evolution begins to degrade device performance) among the photoactive layer. The resulting devices retain 97% of the initial efficiency after 2,000 hours of operation in air (following the ISOS-L-1 international standard), with extrapolated T₈₀lifetime exceeding 100,000 hours.

      This work elucidates how molecular and morphological structures of organic semiconductors govern the device lifetime, and provides a practical pathway toward commercialization of flexible organic photovoltaics.