Electronic structure dynamics in a low bandgap polymer studied by time-resolved photoelectron spectroscopy
| Autor: | Nils Mårtensson, Håkan Rensmo, Ute B. Cappel, Joachim Andreas Terschlüsen, Tomas Edvinsson, Johan Söderström, Anders Sandell, Stefan Plogmaker, Torsten Leitner, Olof Karis, Hans Siegbahn, Svante Svensson, Erik M. J. Johansson |
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| Rok vydání: | 2016 |
| Předmět: |
Organic solar cell
Band gap Chemistry Binding energy Relaxation (NMR) General Physics and Astronomy 02 engineering and technology Electronic structure 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 7. Clean energy 0104 chemical sciences X-ray photoelectron spectroscopy Excited state Extreme ultraviolet Physical and Theoretical Chemistry Atomic physics 0210 nano-technology |
| Zdroj: | Physical Chemistry Chemical Physics. 18:21921-21929 |
| ISSN: | 1463-9084 1463-9076 |
| Popis: | Means to measure the temporal evolution following a photo-excitation in conjugated polymers are a key for the understanding and optimization of their function in applications such as organic solar cells. In this paper we study the electronic structure dynamics by direct pump-probe measurements of the excited electrons in such materials. Specifically, we carried out a time-resolved photoelectron spectroscopy (TRPES) study of the polymer PCPDTBT by combining an extreme ultraviolet (XUV) high harmonic generation source with a time-of-flight spectrometer. After excitation to either the 1st excited state or to a higher excited state, we follow how the electronic structure develops and relaxes on the electron binding energy scale. Specifically, we follow a less than 50 fs relaxation of the higher exited state and a 10 times slower relaxation of the 1st excited state. We corroborate the results using DFT calculations. Our study demonstrates the power of TRPES for studying photo-excited electron energetics and dynamics of solar cell materials. |
| Databáze: | OpenAIRE |
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