Experts Develop High-Performance Flexible Organic Solar Cells with Excellent Thermal Stability and Stretchability

Professor Ziyi Ge's research team at the Chinese Academy of Sciences’ (CAS) Ningbo Institute of Materials Technology and Engineering (NIMTE) has created high-performance flexible organic solar cells (OSCs) with good thermal stability and stretchability, accomplishing power conversion efficiency effectiveness (PCE) of over 16.5%.

The observations were published in the journal Matter.

The researchers at NIMTE added polymer guests to the PM6:BTP-eC9 blend film to construct entangled chain networks, which enhanced the blend film’s ductility and morphological stability.

The crack-onset strain of the developed ternary blend membrane is 17.14% greater than that of the traditional binary blend membrane due to the efficient dissipation of local load induced by the entangled structure.

Furthermore, thanks to the ternary heterojunction strategy, a stabilized PCE of 16.52% was obtained for polyethylene terephthalate-substrate-based flexible OSCs with outstanding bending tolerance.

The PCE of the inverted ternary OSCs maintained over 85.5% (about 7.2% greater than the binary system) of its initial efficiency after 250 hours when stored in an N₂-filled glove box at 85 °C, denoting remarkable thermal stability.

Furthermore, the ternary OSCs demonstrated excellent stretchability, with PCE retention of over 88% (roughly 13% higher than the binary system) after 200 stretching cycles at a tensile strain of about 5%.

The study was supported by the National Science Fund for Distinguished Young Scholars, the National Natural Science Foundation of China, the Ningbo S&T Innovation 2025 Major Special Programme, the Key Project of Frontier Science Research of CAS, etc.

Journal Reference:

Song, W., et al. (2022) Entangled structure morphology by polymer guest enabling mechanically robust organic solar cells with efficiencies of over 16.5%. Matter. doi.org/10.1016/j.matt.2022.03.012.