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A Pentacene-based Nanotube Displaying Enriched Electro/Photochemical Activities
摘要： This article reports the synthesis and characterization of a pentacene-based nanotube that exhibits enriched electrochemical and photochemical activities. The nanotube is constructed from a pentacene chromophore and features a tubular conformation with a triangular cross-section, enabling unique electronic and photophysical properties. The study demonstrates the nanotube's ability to facilitate efficient intramolecular charge transfer and triplet-state generation, highlighting its potential for applications in optoelectronic devices and photocatalysis.
关键词： nanotube,electrochemical,pentacene,triplet-state,charge transfer,photochemical
更新于2025-09-04 15:30:14
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Machine Learning-Based Charge Transport Computation for Pentacene
摘要： Insight into the relation between morphology and transport properties of organic semiconductors can be gained using multiscale simulations. Since computing electronic properties, such as the intermolecular transfer integral, using quantum chemical (QC) methods requires a high computational cost, existing models assume several approximations. A machine learning (ML)–based multiscale approach is presented that allows to simulate charge transport in organic semiconductors considering the static disorder within disordered crystals. By mapping ?ngerprints of dimers to their respective transfer integral, a kernel ridge regression ML algorithm for the prediction of charge transfer integrals is trained and evaluated. Since QC calculations of the electronic structure must be performed only once, the use of ML reduces the computation time radically, while maintaining the prediction error small. Transfer integrals predicted by ML are utilized for the computation of charge carrier mobilities using o?-lattice kinetic Monte Carlo (kMC) simulations. Bene?ting from the rapid performance of ML, microscopic processes can be described accurately without the need for phenomenological approximations. The multiscale system is tested with the well-known molecular semiconductor pentacene. The presented methodology allows reproducing the experimentally observed anisotropy of the mobility and enables a fast estimation of the impact of disorder.
关键词： machine learning,multiscale approach,organic semiconductors,charge transport,pentacene
更新于2025-09-04 15:30:14
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Is Vibrational Coherence a Byproduct of Singlet Exciton Fission?
摘要： A phenomenological wavefunction-based model of vibrationally coherent absorption modulation is proposed and applied to reproduce the triplet-triplet absorption spectra of bis-triisopropylsilylethynyl (TIPS)-pentacene, with the objective of testing whether the singlet fission process in that system spontaneously generates coherent vibrational packets, as recently suggested for TIPS-tetracene. The model is parametrized by a complete set of Franck-Condon parameters obtained from methodologically consistent DFT calculations for all relevant normal modes in all relevant electronic states. The results strongly depend on inhomogeneous broadening of absorption bands, which is explicitly included. They very well agree with the recently published experimental coherence spectra of the pertinent system, validating our underlying principal assumption that the singlet fission process, which generates the observed triplet states, is neutral with respect to vibrational coherences. Experimental confirmation of this interpretational posit demonstrates that in the pentacene derivative, apparently in contrast to the case of its tetracene analogue, fission is not a source of vibrational coherence. Our finding suggests that although the singlet fission process may possibly in individual cases induce vibrational coherence, this feature is not a constitutive characteristic of the fission phenomenon.
关键词： DFT calculations,singlet exciton fission,Franck-Condon parameters,TIPS-pentacene,vibrational coherence
更新于2025-09-04 15:30:14