Vibronic spectra of charge-transfer excitons in donor–acceptor molecular crystals

Lalov, I. J.; Supritz, C.; Reineker, P.

doi:10.1016/j.chemphys.2008.05.002

Cited by 5 publications

(4 citation statements)

References 21 publications

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“…In this study, we examine the characteristics and formation mechanism of Fabry–Perot interference fringes in the suboptical gap light emission spectra of the perovskite-like layered material hexyl ammonium lead iodide (HA 2 PbI 4 ) and 1:1 cocrystals of anthracene and pyromellitic dianhydride (A-PMDA). The ability to process semiconducting hybrid organic–inorganic perovskite in solution gives them the potential to transform methods to fabricate optoelectronic technologies including photovoltaic cells, ,,, light-emitting diodes, ,, and lasers. ,, A-PMDA has long been used as a model system to understand the properties of charge-transfer (CT) excitons including fine structure and their coupling to material vibrations. − The ability to reliably control the light emitted by this material may open interesting avenues to interrogate intermolecular interactions in the solid state.…”

Section: Introductionmentioning

confidence: 99%

Probing Fabry–Perot Interference in Self-Assembled Excitonic Microcrystals with Subgap Light Emission

2019

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Establishing a fundamental understanding of the range of optical effects possible in self-assembled excitonic materials remains crucial to the utility of these materials in future optoelectronic and photonic technologies. In this study, we report the observation and subsequent analysis of Fabry–Perot interference intrinsic to two types of self-assembled excitonic crystalline materials: the hybrid organic–inorganic perovskite-like quantum well superlattice structure of hexyl ammonium lead iodide and the charge-transfer cocrystal of anthracene and pyromellitic dianhydride. The observation of Fabry–Perot interference stems from strong suboptical gap photoluminescence (PL) from both materials in a spectral region of very low material absorption. We characterize this subgap PL in each material to propose permanent defect trap excitons, stabilize their energy, and cause subgap light emission in both materials. We use a model developed to explain interference in the photoluminescence of vacuum-deposited thin films to estimate the thickness, mid-bandgap index of refraction, and surface roughness of our samples. These results indicate that self-assembled excitonic materials may have use in applications such as laser amplifiers, frequency discriminators, and single photon emitters.

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Section: Introductionmentioning

confidence: 99%

Probing Fabry–Perot Interference in Self-Assembled Excitonic Microcrystals with Subgap Light Emission

2019

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“…In a stack without inversion center all components p F , l s , l a may be different from zero and the linear optical susceptibility has to be calculated using the full Hamiltonian (6). This more general case will be discussed in a future publication [7].…”

Section: Excitonic and Vibronic Line Shapesmentioning

confidence: 99%

“…Furthermore it is assumed that both D and A each are coupled to a vibrational mode of frequencies o d and o ac . The Hamiltonian of the system [4][5][6][7] H ¼Ĥ F þĤ C þĤ FC þĤ P þĤ EP (1) is given by the contributions of the FEs, of the CTEs, of the coupling between FEs and CTEs, of the phonons and of the coupling between excitons and phonons. They arê…”

Section: Model Hamiltonianmentioning

confidence: 99%

Donor–acceptor molecular aggregates: Vibronic spectra of mixed Frenkel and charge-transfer excitons

Warns

Lalov

Reineker

2009

Journal of Luminescence

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“…In the present paper we follow the vibronic approach developed and successfully applied in our previous papers, [20][21][22] in which one-dimensional models have been considered. Our present 2D study seems to be more realistic, especially for the case of polyacenes.…”

Section: Introductionmentioning

confidence: 99%

Excitonic and vibronic spectra of Frenkel excitons in a two-dimensional simple lattice

Lalov¹,

Zhelyazkov²

2013

Chemical Physics

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Excitonic and vibronic spectra of Frenkel excitons (FEs) in a two-dimensional (2D) lattice with one molecule per unit cell have been studied and their manifestation in the linear absorption is simulated. We use the Green function formalism, the vibronic approach (see Lalov and Zhelyazkov [Phys. Rev. B 75, 245435 (2007)]), and the nearest-neighbor approximation to find expressions of the linear absorption lineshape in closed form (in terms of the elliptic integrals) for the following 2D models: (a) vibronic spectra of polyacenes (naphthalene, anthracene, tetracene); (b) vibronic spectra of a simple hexagonal lattice. The two 2D models include both linear and quadratic FE-phonon coupling. Our simulations concern the excitonic density of state (DOS), and also the position and lineshape of vibronic spectra (FE plus one phonon, FE plus two phonons). The positions of manyparticle (MP-unbound) FE-phonon states, as well as the impact of the Van Hove singularities on the linear absorption have been established by using typical values of the excitonic and vibrational parameters. In the case of a simple hexagonal lattice the following types of FEs have been considered: (i) non-degenerate FEs whose transition dipole moment is perpendicular to the plane of the lattice, and (ii) degenerate FEs with transition dipole moments parallel to the layer. We found a cumulative impact of the linear and quadratic FE-phonon coupling on the positions of vibronic maxima in the case (ii), and a compensating impact in the case (i).

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Vibronic spectra of charge-transfer excitons in donor–acceptor molecular crystals

Cited by 5 publications

References 21 publications

Probing Fabry–Perot Interference in Self-Assembled Excitonic Microcrystals with Subgap Light Emission

Probing Fabry–Perot Interference in Self-Assembled Excitonic Microcrystals with Subgap Light Emission

Donor–acceptor molecular aggregates: Vibronic spectra of mixed Frenkel and charge-transfer excitons

Excitonic and vibronic spectra of Frenkel excitons in a two-dimensional simple lattice

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