A team of engineers and scientists that comprises scientists from The University of Texas at Austin has developed a new class of materials that can absorb low energy light and convert it into higher energy light.
The new class of materials has the ability to turn long-wavelength photons into short-wavelength blue or ultraviolet photons. Image Credit: University of Texas at Austin
The new material is made of ultra-small silicon nanoparticles and organic molecules closely associated with the ones employed in OLED TVs. This new composite successfully moves electrons between its inorganic and organic components, with applications for more successful solar panels, precise medical imaging, and improved night vision goggles.
The material is explained in a new paper published in Nature Chemistry.
This process gives us a whole new way of designing materials. It allows us to take two extremely different substances, silicon and organic molecules, and bond them strongly enough to create not just a mixture, but an entirely new hybrid material with properties that are completely distinct from each of the two components.
Sean Roberts, Associate Professor, Chemistry, University of Texas at Austin
Composites are built of two or more components that take on exclusive properties when combined. For instance, composites of carbon resins and fibers find application as lightweight materials for racing cars, airplane wings, and several sporting products. In the study co-authored by Roberts, the organic and inorganic components are integrated to show exclusive interaction with light.
Among those properties are the capacity to turn long-wavelength photons—the type seen in red light, which moves well through fog, tissue, and liquids—into short-wavelength blue or ultraviolet photons, which are the type that typically makes sensors function or generate a range of chemical reactions.
This implies the material could be valuable in new technologies as varied as light-based 3D printing, bioimaging, and light sensors that can be employed to aid self-driving cars in traveling through the fog.
This concept may be able to create systems that can see in near infrared. That can be useful for autonomous vehicles, sensors, and night vision systems.
Sean Roberts, Associate Professor, Chemistry, University of Texas at Austin
Also, taking low energy light and making it higher energy can aid in boosting the efficacy of solar cells by enabling them to capture near-infrared light that would usually pass via them. When the technology is regulated, capturing low energy light has the potential to minimize the solar panels’ size by 30%.
Members of the study group, comprising researchers from the University of California Riverside, the University of Colorado Boulder, and the University of Utah, have been working on light conversion of this type for many years. In a previous paper, they successfully explained connecting anthracene—an organic molecule that can emit blue light—with silicon, which is a material employed in many semiconductors and solar panels.
Hoping to increase the interaction among these materials, the group built a new approach for forging electrically conductive bridges between silicon nanocrystals and anthracene. The subsequent strong chemical bond amplifies the pace with which the two molecules can exchange energy, almost doubling the efficacy in transforming lower energy light to higher energy light, in comparison with the previous breakthrough of the team.
The study was financially supported by the National Science Foundation, The Welch Foundation, the W.M. Keck Foundation, and the Air Force Office of Scientific Research.
Kefu Wang and Ming Lee Tang of University of Utah, R. Peyton Cline and Joel D. Eaves of University of Colorado Boulder, Joseph Schwan and Lorenzo Mangolini of University of California Riverside, and Jacob M. Strain of UT Austin also add up widely to the study.
Journal Reference:
Wang, K., et al. (2023). Efficient photon upconversion enabled by strong coupling between silicon quantum dots and anthracene. Nature Chemistry. doi.org/10.1038/s41557-023-01225-x.