To unravel this mystery the researchers used time- and angle-resolved photoemission spectroscopy, a cutting-edge technique to observe the dynamics of electrons on the femtosecond time scale, which is a billionth of a millionth of a second. “It was an open and very disputed question whether a photon excites two electrons directly or initially one electron, which subsequently shares its energy with another electron.” Ralph Ernstorfer, a senior author of the study. ”When pentacene is excited by light, the electrons in the material rapidly react,” explains Prof.
Fission fission meaning movie#
A team of researchers at the Fritz Haber Institute of the Max Planck Society, the Technical University of Berlin, and the Julius-Maximilians-Universität of Würzburg have now deciphered the first step of this process by recording an ultrafast movie of the photon-to-electricity conversion process, resolving a decades-old debate about the mechanism of the process. This excitation doubling, which is called exciton fission, could be extremely useful for high-efficiency photovoltaics, specifically to upgrade the dominant technology based on silicon. Only a few molecular materials like pentacene are an exception, where one photon is converted to two electrons instead. In a solar cell, the energy of a single photon is transferred to a single electron of the material, but no more than one. Since the days of Max Planck and Albert Einstein, we know that light as well as electricity are quantized, meaning they come in tiny packets called photons and electrons. Photovoltaics, the conversion of light to electricity, is a key technology for sustainable energy. Researchers have resolved the mechanism of exciton fission, which could increase solar-to-electricity efficiency by one-third, potentially revolutionizing photovoltaic technology. Photovoltaic technology, which converts light into electricity, could be significantly upgraded by a process called exciton fission found in materials like pentacene, wherein one photon excites two electrons.
Emergence of the bitriplet exciton in crystalline pentacene.
0 kommentar(er)
