Tin-Based Perovskite Solar Cells Slow Hot-Electron Heat Loss 1,000-Fold, Researchers Say

When sunlight strikes a solar panel, photons jump-start electrons into action. The most energetic photons create super-charged hot electrons. These high-energy particles normally cool in fractions of a trillionth of a second, dumping their bonus energy as waste heat before they can leave the solar cell. That rapid cooling has been a barrier to using hot electrons to boost power output.

Working with Maria Antonietta Loi, professor of Photophysics and Optoelectronics, the team created an experimental setup. Using a specialized solar cell material called tin-based perovskite, Loi’s lab performed what the report described as a feat many thought impossible: it slowed the heat loss down by a factor of 1,000. The extra energy lingered for nanoseconds instead of vanishing in picoseconds.

To explain the result, Koster and PhD student Tim Faber built digital simulations to peel back the quantum layers. They found a surprising double-action mechanism at work. The simulations matched the exact nanosecond delay observed in the lab, according to the report.

Tin-based metal halide perovskites are non-toxic, eco-friendly crystalline materials for high-performance solar energy conversion, the report said. The material has an unusually low electron mass. As a result, electric charges move quickly and retain extra thermal energy for extended periods. That combination of broad light absorption, efficient charge movement and prolonged energy retention makes these materials prime candidates for next-generation solar panels.

In their announcement, the team said: “There are many other questions that still need answers, but in theory, this discovery could allow the creation of more efficient solar cells, beyond the theoretical limit of 33 percent.”

The report was shared by long-time Slashdot reader fahrbot-bot.