Observation of an Ultrafast Exciton Hopping Channel in Organic Semiconducting Crystals
| Autor: | Ti Wang, Tika R. Kafle, Wai-Lun Chan, Bhupal Kattel |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Exciton
02 engineering and technology 010402 general chemistry 01 natural sciences Molecular physics Condensed Matter::Materials Science symbols.namesake Physics::Chemical Physics Physical and Theoretical Chemistry Diffusion (business) Biexciton Condensed Matter::Other business.industry Chemistry Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Photoexcitation Organic semiconductor General Energy Picosecond Excited state symbols Optoelectronics 0210 nano-technology business Raman spectroscopy |
| Zdroj: | The Journal of Physical Chemistry C. 120:7491-7499 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/acs.jpcc.6b01400 |
| Popis: | One of the major challenges in using organic semiconductors for photovoltaics is their extremely short exciton diffusion length. Recently, a number of studies have shown that the exciton transport range within the first few picoseconds after photoexcitation can be comparable to the exciton’s diffusion length over its entire lifetime. The origin of this fast transport channel is often attributed to the large spatial coherent size of the exciton right after photoexcitation. Here we observe an ultrafast exciton hopping channel in titanyl phthalocyanine crystals even though the exciton coherent size is a few times smaller than the transport range. This channel operates only within the first few picoseconds after photoexcitation and has a hopping rate that is an order of magnitude faster than the typical Forster resonance energy transfer rate. Resonant Raman spectroscopy shows that the optically excited exciton is strongly mixed with the macrocycle vibrational mode of the phthalocyanine molecules. A hypothesis... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|