Picosecond time resolved photoluminescence spectroscopy of a tetracene film on highly oriented pyrolytic graphite: Dynamical relaxation, trap emission, and superradiance

Voigt, Monika; Langner, Andreas; Schouwink, P.; Lupton, John M.; Mahrt, Rainer F.; Sokołowski, M.

doi:10.1063/1.2766944

Cited by 45 publications

(76 citation statements)

References 31 publications

(20 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 4b shows that as exciton diffusion proceeds, the emission spectrum red shifts faster near the centre of the spatial distribution (x ¼ 0) than in regions on the periphery of the distribution. This observation is consistent with the presence of exciton energy traps 34 . Namely, as the diffusion proceeds, exciton traps are filled faster in the centre of the distribution, where the triplet density is higher and more trap sites can be sampled.…”

Section: Article Nature Communications | Doi: 101038/ncomms4646supporting

confidence: 80%

Visualization of exciton transport in ordered and disordered molecular solids

et al. 2014

View full text Add to dashboard Cite

Transport of nanoscale energy in the form of excitons is at the core of photosynthesis and the operation of a wide range of nanostructured optoelectronic devices such as solar cells, lightemitting diodes and excitonic transistors. Of particular importance is the relationship between exciton transport and nanoscale disorder, the defining characteristic of molecular and nanostructured materials. Here we report a spatial, temporal and spectral visualization of exciton transport in molecular crystals and disordered thin films. Using tetracene as an archetype molecular crystal, the imaging reveals that exciton transport occurs by random walk diffusion, with a transition to subdiffusion as excitons become trapped. By controlling the morphology of the thin film, we show that this transition to subdiffusive transport occurs at earlier times as disorder is increased. Our findings demonstrate that the mechanism of exciton transport depends strongly on the nanoscale morphology, which has wide implications for the design of excitonic materials and devices.

show abstract

Section: Article Nature Communications | Doi: 101038/ncomms4646supporting

confidence: 80%

Visualization of exciton transport in ordered and disordered molecular solids

et al. 2014

View full text Add to dashboard Cite

show abstract

“…55 The resultant lower state is radiative with a dipole polarized along the b-axis, which can contribute to superradiant emission. 50,51,56 In the single crystals we studied, the emission spectra show significant polarization dependence ( Fig. 1(b)) with an intensity ratio of ~ 15 at room temperature between the polarizations that are parallel and perpendicular to the b-axis, respectively.…”

Section: A Crystalline Structure and Fluorescence Spectramentioning

confidence: 99%

Polarization-dependent exciton dynamics in tetracene single crystals

Zhang

et al. 2014

The Journal of Chemical Physics

View full text Add to dashboard Cite

Abstract:We conduct polarization-dependent ultrafast spectroscopy to study the dynamics of singlet fission in tetracene single crystals. The spectrotemporal species for singlet and triplet excitons in transient absorption spectra are found to be strongly dependent on probe polarization. By carefully analyzing the polarization dependence, the signals contributed by different transitions related to singlet excitons have been disentangled, which is further applied to construct the correlation between dynamics of singlet and triplet excitons. The anisotropy of exciton dynamics provides an alternative approach to tackle the long-standing challenge in understanding the mechanism of singlet fission in organic semiconductors.

show abstract

“…The number of coherently coupled chromophores, N coh , has been estimated from the superradiative enhancement of the excited state decay rate [16][17][18][19][20][21][22], analysis of the inhomogeneous linewidth of the excitonic absorption spectrum [23,24] and from the peak-to-dip spectral separation in the transient absorption spectrum. [15,[25][26][27] However, all such methods neglect the important role of vibronic coupling in the 0 1 S S → UV-Vis transition from which the exciton band is derived.…”

Section: Introductionmentioning

confidence: 99%

Determining the spatial coherence of excitons from the photoluminescence spectrum in charge-transfer J-aggregates

Hestand

Spano

2016

Chemical Physics

View full text Add to dashboard Cite

The importance of spatial coherence in energy and charge transfer processes in biological systems and photovoltaic devices has been hotly debated over the past several years. While larger spatial coherences are thought to benefit transport, a clear correlation has yet to be established, partly because a simple and accurate measure of the coherence length has, for the most part, remained elusive. Previously, it was shown that the number of coherently connected chromophores, Coh N , can be determined directly from the ratio ( R S ) of the 0-0 and 0-1 vibronic line strengths in the photoluminescence (PL) spectrum. The relation,where 2 0 λ is the associated Huang-Rhys parameter, was derived in the Frenkel exciton limit. Here, it is shown that R S remains a highly accurate measure of coherence for systems characterized by significant charge transfer interactions (e.g. conjugated π-stacked systems). The only requirement is that the exciton band curvature must be positive, as in a J-aggregate.

show abstract

Picosecond time resolved photoluminescence spectroscopy of a tetracene film on highly oriented pyrolytic graphite: Dynamical relaxation, trap emission, and superradiance

Cited by 45 publications

References 31 publications

Visualization of exciton transport in ordered and disordered molecular solids

Visualization of exciton transport in ordered and disordered molecular solids

Polarization-dependent exciton dynamics in tetracene single crystals

Determining the spatial coherence of excitons from the photoluminescence spectrum in charge-transfer J-aggregates

Contact Info

Product

Resources

About