Concept of the Time-Dependent Diffusion Coefficient of Polarons in Organic Semiconductors and Its Determination from Time-Resolved Spectroscopy
| Autor: | Petr Toman, Miroslav Menšík, Jiří Pfleger, Bartosz Paruzel, David Rais |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
education.field_of_study
Materials science Absorption spectroscopy Population 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Kinetic energy Polaron 01 natural sciences Molecular physics 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Organic semiconductor General Energy Ultrafast laser spectroscopy Physical and Theoretical Chemistry Diffusion (business) Time-resolved spectroscopy 0210 nano-technology education |
| Zdroj: | The Journal of Physical Chemistry C. 122:22876-22883 |
| ISSN: | 1932-7455 1932-7447 |
| Popis: | The population of photogenerated species in organic semiconductors may decay due to their mutual annihilation upon collisions during their diffusive motion. The standard kinetic models for the population decay, n(t), assume a time-invariant diffusion coefficient, i.e., D(t) ≡ constant. This leads to a failure in predicting the experimentally observed temporal evolution of photogenerated species if it asymptotically approaches a power-law decay n(t) ∼ t–x, with x < 0.5. We have used a concept of the time-dependent diffusion coefficient and developed a novel mathematical method of its determination from decay collision rates obtained by transient optical absorption spectroscopy. We tested the applicability of this method on the interpretation of data of the decay of polaron population obtained experimentally by time-resolved transient absorption measurements on thin films of regioregular poly(3-hexylthiophene), where we recently reported a power-law asymptote with x = 0.24. While we do not assume any micros... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|