APPLICATIONS OF TECHNOLOGY:
- 1,000X light absorption enhancement
- Drop in replacement for lanthanide nanoparticles
- Higher UV absorption without effect on downconversion or reemission
Berkeley Lab researchers Peter Agbo and Rebecca Abergel have improved the efficiency of downconverting lanthanide nanoparticles by using the ligand 3,4,3-LI (1,2-HOPO) as an ultraviolet photosensitizer of NaGd1-xEuxF4 nanoparticles to create a UV downconverting material emitting light at wavelengths where the photocurrent response of silicon photovoltaics is higher. The construct is an effective downconverter of UV light into the red-frequency emissions. The inventors estimate a 1,000x-improvement in UV absorption efficiency with this ligand, and potentially greater improvement with optimized ligands.
In the Berkeley Lab technology, the ligand acts like antennas, increasing the UV absorption cross-section of the nanoparticles, and therefore the UV absorption efficiency, without affecting the downconversion or reemission processes. Testing resulted in 610 nm downconversion luminescence upon 317 nm excitation.
The problem of spectral mismatch between semiconductor band gaps and the Earth’s terrestrial solar spectrum limits the efficiency of modern photovoltaics. While a number of methods have been implemented to focus on the problem of light upconversion, little work has addressed the challenge of UV downconversion towards the low-energy visible and near-infrared regimes, where the photocurrent response for bulk silicon is highest. Maturation of downconverter prototypes has been inhibited by the low molar absorptivities of f‒f transitions. In addition, most lanthanide nanoparticles have very low absorption efficiency, so researchers often resort to high-powered lasers to test absorption, downconversion, and reemission.
DEVELOPMENT STAGE: Proven principle.
FOR MORE INFORMATION:
STATUS: Patent pending. Available for licensing or collaborative research.
SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD: