Researchers at the University of California, Irvine (UCI) have developed a groundbreaking method for light and matter interaction, paving the way for ultrathin silicon solar cells.
This innovation, outlined in a recent cover article in ACS Nano, promises to expand solar energy applications to areas such as thermoelectric clothing and onboard vehicle charging.
The UCI team’s research, conducted alongside scientists from Russia’s Kazan Federal University and Tel Aviv University, focuses on transforming pure silicon from an indirect to a direct bandgap semiconductor.
This transformation is achieved by altering the way silicon interacts with light, rather than changing the material itself.
By conditioning the light and confining photons on nanoscale structures near the semiconductor, the researchers enhanced the photons’ momentum, significantly improving light absorption and device performance.
New technology enables direct bandgap behavior in silicon, promoting effective solar energy conversion.This advancement enables electrons to transition more efficiently from the valence band to the conduction band in silicon, which typically requires an additional particle, a phonon, to facilitate momentum transfer.
Lead author Dmitry Fishman explained that silicon’s inherent optical weaknesses have hampered solar energy conversion efforts, despite its abundance.
“By giving photons momentum, we can excite electrons without needing extra particles, transforming light-matter interactions,” he stated.
The implications are vast: with traditional solar cells requiring thick layers of silicon to capture sufficient sunlight—driving up costs and decreasing efficiency—the new ultrathin solar cells could revolutionize solar technology.
Co-author Eric Potma emphasized the urgency of this innovation in light of climate change, advocating for a transition from fossil fuels to renewable energy sources.
The project received support from the Chan Zuckerberg Initiative, and its findings could significantly impact the future of photo-sensing and light-energy conversion technologies.