While spectroscopic measurements are normally averaged over myriad molecules, a new method developed by researchers at the Technical University of Munich (TUM) provides precise information about the interaction of individual molecules with their environment. This will accelerate the identification of efficient molecules for future photovoltaic technologies, for example.
An international team led by the TUM chemist Professor Jürgen Hauer has now succeeded in determining the spectral properties of individual molecules.
The researchers acquired the absorption and emission spectra of the investigated molecules over a broad spectral range in a single measurement to accurately determine how the molecules interact with their environment, capturing and releasing energy.
Normally, these kinds of measurements are averaged over thousands, even millions, of molecules, sacrificing important detail information. "Previously, emission spectra could be routinely acquired, but absorption measurements on individual molecules were extremely expensive," explains Hauer. "We have now attained the ultimate limit of detectability."
Compact apparatus, quick measurement
The new method is based on a compact, merely DIN-A4-sized instrument that the Munich chemists developed in collaboration with colleagues at the Politecnico di Milano.
The key: It generates a double laser pulse with a controlled delay in between. The second pulse modulates the emission spectrum in a specific manner, which in turn provides information about the absorption spectrum. This information is then evaluated using a Fourier transformation.
"The primary advantage is that we can, with little effort, transform a conventional measurement setup for acquiring emission spectra into a device for measuring emission and absorption spectra," says Hauer. The measurement itself is relatively easy. "At nine o'clock in the morning, we installed the apparatus into the setup at the University of Copenhagen," says Hauer. "At half past eleven, already, we had our first useful measurement data."
On the tracks of photosynthesis
Using the new spectroscopy method, chemists hope to now study individual molecules, to understand phenomena such as the energy flow in metal-organic compounds and physical effects in molecules when they come into contact with water and other solvents.
The influence of solvents at the single molecule level is still poorly understood. The chemists also want to display the flow of energy in a time-resolved manner to understand why energy flows faster and more efficiently in certain molecules than in others. "Specifically, we are interested in the transfer of energy in biological systems in which photosynthesis takes place," says Hauer.
The goal: organic solar cells
The researchers have cast their view on the light collection complex LH2 for future applications. "Once we understand the natural light-harvesting complexes, we can start thinking about artificial systems for deployment in photovoltaics," says Hauer. The findings could form the basis for future technologies in photovoltaics. The goal is the development of a novel organic solar cell.
The research was supported by the European Research Council (ERC), the European Initiative Laserlab-Europe, the Austrian Fund for the Promotion of Scientific Research (FWF) and the Danish Council of Independent Research (DFF). The publication resulted from a cooperation between the Politecnico di Milano, the University of Copenhagen and the TU Munich.
Prof. Dr. Jürgen Hauer
Technical University of Munich
Lichtenbergstr. 4, 85748 Garching, Germany
Tel.: +49 89 289 13420 – E-Mail: firstname.lastname@example.org
Single-molecule excitation–emission spectroscopy
Erling Thyrhaug, Stefan Krause, Antonio Perri, Giulio Cerullo, Dario Polli, Tom Vosch, and Jürgen Hauer
PNAS, 15.02.2019 – DOI: 10.1073/pnas.1808290116
https://www.tum.de/en/about-tum/news/press-releases/detail/article/35275/ Link to the press release
Dr. Ulrich Marsch | Technische Universität München
Phagocytes versus killer cells - A closer look into the tumour tissue
21.10.2019 | Universität Duisburg-Essen
How intestinal cells renew themselves – the role of Klumpfuss in cell differentiation
21.10.2019 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)
A very special kind of light is emitted by tungsten diselenide layers. The reason for this has been unclear. Now an explanation has been found at TU Wien (Vienna)
It is an exotic phenomenon that nobody was able to explain for years: when energy is supplied to a thin layer of the material tungsten diselenide, it begins to...
Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich have explored the initial consequences of the interaction of light with molecules on the surface of nanoscopic aerosols.
The nanocosmos is constantly in motion. All natural processes are ultimately determined by the interplay between radiation and matter. Light strikes particles...
Particles that are mere nanometers in size are at the forefront of scientific research today. They come in many different shapes: rods, spheres, cubes, vesicles, S-shaped worms and even donut-like rings. What makes them worthy of scientific study is that, being so tiny, they exhibit quantum mechanical properties not possible with larger objects.
Researchers at the Center for Nanoscale Materials (CNM), a U.S. Department of Energy (DOE) Office of Science User Facility located at DOE's Argonne National...
A new research project at the TH Mittelhessen focusses on the development of a novel light weight design concept for leisure boats and yachts. Professor Stephan Marzi from the THM Institute of Mechanics and Materials collaborates with Krake Catamarane, which is a shipyard located in Apolda, Thuringia.
The project is set up in an international cooperation with Professor Anders Biel from Karlstad University in Sweden and the Swedish company Lamera from...
Superconductivity has fascinated scientists for many years since it offers the potential to revolutionize current technologies. Materials only become superconductors - meaning that electrons can travel in them with no resistance - at very low temperatures. These days, this unique zero resistance superconductivity is commonly found in a number of technologies, such as magnetic resonance imaging (MRI).
Future technologies, however, will harness the total synchrony of electronic behavior in superconductors - a property called the phase. There is currently a...
02.10.2019 | Event News
02.10.2019 | Event News
19.09.2019 | Event News
21.10.2019 | Materials Sciences
21.10.2019 | Materials Sciences
21.10.2019 | Medical Engineering