Spacer layout boosts performance of single component organic solar cells

by Riko Seibo
Tokyo, Japan (SPX) Jan 15, 2026

The performance of single component organic solar cells depends strongly on the spacer units built into their molecular design. Spacer attachment position on a double cable polymer backbone has received much less attention than other structural parameters, even though it can influence how the material arranges and operates in a device.

To close this gap, researchers adopted a spacer isomerization engineering strategy and prepared two isomeric double cable conjugated polymers by changing where the spacer attaches on an indenone benzene ring. By shifting this attachment position, they could precisely regulate molecular packing and film crystallinity, both of which play a central role in exciton dissociation efficiency, charge transport, and overall power conversion efficiency in single component organic solar cells.

The team reports that this structural tuning effectively optimizes molecular packing, leading to more ordered films and improved pathways for charge carriers. Better packing and crystallinity help excitons separate more efficiently at internal interfaces, which in turn supports higher current and voltage outputs from the devices.

When used as the active layer in single component organic solar cells, the isomeric polymers deliver enhanced photovoltaic performance compared with structures that do not exploit spacer isomerization. The same materials also show strong results when introduced as a third component in ternary organic solar cells, where they help refine the donor acceptor interface and promote balanced charge generation and transport.

In both roles, whether as the sole active component or as an additive in ternary systems, the polymers exhibit excellent thermal stability. Device characteristics remain robust under elevated temperature conditions, indicating that the structural changes introduced through spacer isomerization do not compromise stability and may help support long term operation.

The authors describe spacer isomerization engineering as a simple and effective design strategy for next generation double cable conjugated polymers. They suggest that careful control over spacer attachment position can guide the development of high performance and stable single component organic solar cells that provide an alternative to more complex multicomponent blends.

Research Report:Spacer isomerization engineering in double-cable conjugated polymers for optimized molecular packing and enhanced photovoltaic performance