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| Main Authors: | , , , , |
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| Format: | Preprint |
| Published: |
2024
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2403.09851 |
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| _version_ | 1866929277830692864 |
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| author | Steidel, Jakob Michalsky, Ina Ajdari, Mohsen Kivala, Milan Tegeder, Petra |
| author_facet | Steidel, Jakob Michalsky, Ina Ajdari, Mohsen Kivala, Milan Tegeder, Petra |
| contents | Bridged triarylamines, so-called N-heterotriangulenes (N-HTAs) are promising organic semiconductors for applications in optoelectronic devices. Thereby the electronic structure at organic/metal interfaces and within thin films as well as the electronically excited states dynamics after optical excitation is essential for the performance of organic-molecule-based devices. Here, we investigated the energy level alignment and the excited state dynamics of a N-HTA derivative adsorbed on Au(111) by means of energy- and time-resolved two-photon photoemission spectroscopy. We quantitatively determined the energetic positions of several occupied and unoccupied molecular (transport levels) and excitonic states (optical gap) in detail. A transport gap of 3.20 eV and an optical gap of 2.58 eV is determined, resulting in an exciton binding energy of 0.62 eV. With the first time-resolved investigation on a N-HTA compound we gained insights into the exciton dynamics and resolved processes on the femtosecond to picosecond timescale. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2403_09851 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Determination of Energetic Positions of Electronic States and the Exciton Dynamics in a pi-Expanded N-Heterotriangulene Derivative Adsorbed on Au(111) Steidel, Jakob Michalsky, Ina Ajdari, Mohsen Kivala, Milan Tegeder, Petra Materials Science Bridged triarylamines, so-called N-heterotriangulenes (N-HTAs) are promising organic semiconductors for applications in optoelectronic devices. Thereby the electronic structure at organic/metal interfaces and within thin films as well as the electronically excited states dynamics after optical excitation is essential for the performance of organic-molecule-based devices. Here, we investigated the energy level alignment and the excited state dynamics of a N-HTA derivative adsorbed on Au(111) by means of energy- and time-resolved two-photon photoemission spectroscopy. We quantitatively determined the energetic positions of several occupied and unoccupied molecular (transport levels) and excitonic states (optical gap) in detail. A transport gap of 3.20 eV and an optical gap of 2.58 eV is determined, resulting in an exciton binding energy of 0.62 eV. With the first time-resolved investigation on a N-HTA compound we gained insights into the exciton dynamics and resolved processes on the femtosecond to picosecond timescale. |
| title | Determination of Energetic Positions of Electronic States and the Exciton Dynamics in a pi-Expanded N-Heterotriangulene Derivative Adsorbed on Au(111) |
| topic | Materials Science |
| url | https://arxiv.org/abs/2403.09851 |