‘Molecular Catapult’ Boosts Efficiency of Solar Energy Conversion

Scientists have discovered that electrons in solar materials can be propelled across molecules at nearly the fastest speed allowed by nature, driven by tiny atomic vibrations. This breakthrough, challenging long-standing ideas about how solar energy systems function, could pave the way for designing more efficient technologies for capturing sunlight and converting it into electricity.

Unlocking Ultrafast Charge Transfer

Researchers at the University of Cambridge observed electric charge separating during a single molecular vibration, lasting just 18 femtoseconds – less than 20 quadrillionths of a second. This incredibly rapid transfer was achieved in a system deliberately designed to be gradual, according to conventional theory. SciTechDaily reports that instead of drifting randomly, the electron is launched in a coherent burst, with the vibration acting like a “molecular catapult.”

How the ‘Catapult’ Works

At the extremely small timescale of femtoseconds, atoms within molecules are constantly vibrating. The research team observed charge transfer occurring as quickly as these atomic motions. As Dr. Pratyush Ghosh, Research Fellow at St John’s College, Cambridge, and first author of the study, explained, “We’re effectively watching electrons migrate on the same clock as the atoms themselves.”

Organic Solar Cells: A Promising Alternative

The findings have particular relevance for organic solar cells, which utilize carbon-based molecules instead of silicon to convert sunlight into electricity. Yahoo News explains that whereas organic solar cells have the potential to be cheaper than traditional silicon-based cells, they are currently less efficient. A typical organic solar cell consists of an electron donor and an electron acceptor sandwiched between two conductive electrodes. When light strikes the cell, it generates an exciton – an electron-hole pair – which then splits at the interface between the donor and acceptor, generating electricity.

Overcoming Traditional Limitations

Traditionally, achieving fast charge transfer in organic solar cells requires strong electronic coupling between donor and acceptor molecules, as well as a significant energy difference between them. Though, the Cambridge team demonstrated ultrafast charge transfer without needing to meet these conventional requirements. They used a short laser pulse to excite the electron donor, a polymer called TS-P3, and then a different laser to measure the changes during charge transfer. Phys.org reports that the vibrations within the polymer donor molecule launched the electron across the junction to the acceptor molecule, triggering overlapping vibrations that facilitated the rapid transfer.

Implications for Future Solar Technology

The study, published in Nature Communications on March 5, 2026, suggests that instead of trying to suppress molecular motion, materials can be designed to harness it. As study co-author Akshay Rao, a physicist at Cambridge, stated, “Instead of trying to suppress molecular motion, we can now design materials that employ it – turning vibrations from a limitation into a tool.” This discovery establishes new strategies for designing more efficient organic solar cells and materials, potentially leading to a new generation of cost-effective and high-performance solar energy technologies.

Key Takeaways

• Electrons can be propelled across solar materials at nearly the fastest speed allowed by nature using molecular vibrations.
• This “molecular catapult” effect challenges conventional theories about charge transfer in solar energy systems.
• The discovery has significant implications for improving the efficiency of organic solar cells.
• Researchers are now exploring ways to design materials that harness molecular vibrations to enhance solar energy conversion.

Source: Ghosh , P. , Royakkers , J. , Londi , G. , Giannini , S. , Arul , R. , Gillett , AJ , Keene , ST , Zelewski , SJ , Beljonne , D. , Bronstein , H. , & Rao , A. (2026). Vibronically assisted sub-cycle charge transfer at a non-fullerene acceptor heterojunction. Nature Communications, 17(1). https://doi.org/10.1038/s41467-026-70292-8