A new class of materials that can absorb low-energy light and transform it into higher-energy light is a composite of organic (pink) and inorganic (blue) components. Image: University of Texas at Austin.A team of scientists and engineers that includes researchers from the University of Texas at Austin (UT Austin) has created a new class of materials that can absorb low-energy light and transform it into higher-energy light. The new composite material is composed of ultra-small silicon nanoparticles and organic molecules closely related to those utilized in OLED TVs.
This material can efficiently move electrons between its organic and inorganic components, and could lead to the development of more efficient solar panels, more accurate medical imaging and better night-vision goggles. The researchers report the novel material in a paper in Nature Chemistry.
“This process gives us a whole new way of designing materials,” said Sean Roberts, an associate professor of chemistry at UT Austin. “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.”
Composite materials are composed of two or more components that adopt unique properties when combined. For example, composites of carbon fibers and resins find use as lightweight materials for airplane wings, racing cars and many sporting products. In this study, the researchers combined inorganic and organic components to produce a composite material that displays a unique interaction with light.
Among the material’s properties is the ability to turn long-wavelength photons – the type found in red light, which tends to travel well though tissue, fog and liquids – into short-wavelength blue or ultraviolet photons, which are the type that usually make sensors work or produce a wide range of chemical reactions. This means the material could prove useful in technologies as diverse as bioimaging, light-based 3D printing and light sensors that can be used to help self-driving cars travel through fog.
“This concept may be able to create systems that can see in near-infrared,” Roberts said. “That can be useful for autonomous vehicles, sensors and night-vision systems.”
Taking low-energy light and making it higher energy can also potentially help to boost the efficiency of solar cells by allowing them to capture near-infrared light that would normally pass straight through. When this technology is optimized, it could help to reduce the size of solar panels by 30% through the capture of this low-energy light.
Members of the research team, which included scientists 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 several years. In a previous paper in Nature Chemistry, they described successfully connecting anthracene, an organic molecule that can emit blue light, with silicon, a material used in solar panels and in many semiconductors.
Seeking to amplify the interaction between these materials, the team has now developed a new method for forging electrically conductive bridges between anthracene and silicon nanocrystals. The resulting strong chemical bond increases the speed with which the two molecules can exchange energy, almost doubling the efficiency with which they convert lower-energy light into higher-energy light, compared with the team’s previous breakthrough.
This story is adapted from material from the University of Texas at Austin, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.