Nanoparticles with innovative electronic properties
Researchers of the Chair of Organic Chemistry II at the University of Erlangen-Nuremberg (FAU) have developed a concept to control alumina nanoparticles.
Researchers at the Chair of Organic Chemistry II at FAU have discovered that it is possible to control the optical and electronic properties of aluminium oxide nanoparticles, despite the fact that they are typically electronically inert and optically inactive. They have now designed a concept for managing these doubly functionalized nanoparticles. They have published their findings in the journal ‘Chemistry – A European Journal’ (DOI: 10.1002/chem.201901052).
The researchers succeeded in grafting a phosphonic acid derivative onto the oxide surface of the nanoparticles. This led the usually virtually transparent and colorless particles to emit an intense turquoise fluorescence. At the next stage an amphiphile, a substance which is soluble in both fat and water, was formed at the surface, fundamentally changing the optical and electronic behavior of the originally mono-functionalized nanoparticles. If nanoparticles functionalized in this way are excited in the wavelength spectrum, electrons are transferred to the components which have fewer electrons. The turquoise-colored fluorescence of the electron-rich nanoparticles is reduced and, depending on the concentration of the electron-poor amphiphile, an orange-colored fluorescence is reached step by step. Finally, the particles emit a pale pink color in daylight.
Prof. Dr. Andreas Hirsch, Chair of Organic Chemistry II, has developed this concept as part of his fundamental research conducted with research associate Lisa Stiegler.