Polymer Photovoltaic Devices and Performance

Polymer photovoltaic devices, commonly referred to as organic solar cells, harness conjugated polymers as light‐absorbing donor materials paired with electron acceptors to convert sunlight into electrical energy. Bulk heterojunction architectures dominate, where interpenetrating donor and acceptor phases form a nanoscale blend facilitating efficient exciton dissociation and charge transport. Key performance metrics include power conversion efficiency (PCE), fill factor, open‐circuit voltage and device stability under prolonged illumination. Advances in molecular design, such as tuning backbone electronic properties, optimising side‐chain length and promoting regioregularity, have steadily driven PCE beyond 18 per cent in single‐junction devices. Morphological control through thermal or solvent annealing and additive engineering yields finely tuned donor–acceptor domains, balancing charge carrier mobility and exciton separation. The shift from fullerene to non‐fullerene acceptors has expanded absorption into the near‐infrared, improved energy‐level alignment and enhanced photostability. Flexible substrates and roll‐to‐roll processing techniques point to low‐cost, large‐area manufacture. Current challenges centre on maintaining high efficiency under operational stress, minimising energy losses during charge transfer and developing sustainable materials for upscaling. Global significance arises from the potential for lightweight, semitransparent and wearable photovoltaics addressing decentralised energy demands with reduced environmental footprint.

Research from Nature Portfolio

Recent studies have revealed that controlling polymer aggregation and phase morphology is pivotal for high‐efficiency devices. By tuning donor polymer crystallinity through temperature‐dependent aggregation, near‐ideal polymer:fullerene morphologies can be achieved, yielding thick‐film solar cells with efficiencies exceeding 10 per cent and enhanced fill factors. This work establishes general design rules that enable multiple donor–acceptor combinations to reach high performance without reliance on a singular material pairing. Complementary research has demonstrated that regioregularity in narrow‐bandgap polymers significantly improves charge transport and photovoltaic activity. Polymers with highly ordered backbone sequences translate to more coherent bulk morphologies, reduced trap states and enhanced device voltages. These insights into molecular order–bulk structure relationships underpin strategies to elevate both efficiency and operational stability in emerging polymer solar cells.

Polymer Photovoltaic Devices and Performance publication trend

The graph below shows the total number of articles in polymer photovoltaic devices and performance across all publications each year (not limited to Nature Index journals).

Technical terms

Power conversion efficiency (PCE): The ratio of electrical power output to incident solar power, indicating device performance.

Bulk heterojunction (BHJ): A nano-intermixed donor–acceptor blend forming continuous pathways for exciton dissociation and charge transport.

Regioregularity: The uniform arrangement of monomer units along a polymer backbone, enhancing chain packing and charge mobility.

Highest occupied molecular orbital (HOMO) / Lowest unoccupied molecular orbital (LUMO): Frontier energy levels governing exciton dissociation, open-circuit voltage and charge transfer.

Exciton: A bound electron–hole pair created upon photon absorption that must reach a donor–acceptor interface to generate free charges.

References

1. Research progress and application of high efficiency organic solar cells based on benzodithiophene donor materials. Exploration (2024).
2. Aggregation and morphology control enables multiple cases of high-efficiency polymer solar cells. Nature Communications (2014).
3. Regioregular narrow-bandgap-conjugated polymers for plastic electronics. Nature Communications (2017).
4. Non-Fullerene Electron Acceptors for Use in Organic Solar Cells. Accounts of Chemical Research (2015).
5. Effect of Systematically Tuning Conjugated Donor Polymer Lowest Unoccupied Molecular Orbital Levels via Cyano Substitution on Organic Photovoltaic Device Performance. Chemistry of Materials (2016).
6. Effect of side chain length on the charge transport, morphology, and photovoltaic performance of conjugated polymers in bulk heterojunction solar cells. Journal of Materials Chemistry A (2016).