Related papers: Exciton properties of selected aromatic hydrocarbo…
The exciton dispersion is examined in the case of four selected prototypical molecular solids: pentacene,tetracene,picene,chrysene. The model parameters are determined by fitting to experimental data obtained by inelastic electron…
We have studied the low-energy electronic excitations of solid picene at 20 K using momentum dependent electron energy-loss spectroscopy. Our results demonstrate the presence of five excitonic features below the transport energy gap of…
Covalently linked acene dimers are of interest as candidates for intramolecular singlet fission. We report many-electron calculations of the energies and wavefunctions of the optical singlets, the lowest triplet exciton and the…
We have carried out electron energy-loss investigations of the lowest singlet excitons in pentacene at 20 K. Our studies allow to determine the full exciton band structure in the a*,b* reciprocal lattice plane. The lowest singlet exciton…
We show from many-body quantum mechanical calculations that there occur structurally distinct triplet-pair eigenstates in the intramolecular singlet fission (iSF) compound pentacene-tetracene-pentacene. Triplet excitons occupy neigboring…
We present a comparative study of ultrafast photo-conversion dynamics in tetracene (Tc) and pentacene (Pc) single crystals and Pc films using optical pump-probe spectroscopy. Photo-induced absorption in Tc and Pc crystals is activated and…
Linear and non-linear spectroscopies are powerful tools used to investigate the energetics and dynamics of electronic excited states of both molecules and crystals. While highly accurate \emph{ab initio} calculations of molecular spectra…
Laser-induced fluorescence spectra and excitation lifetimes of anthracene, tetracene, and pentacene molecules attached to the surface of solid argon clusters have been measured with respect to cluster size, density of molecules and…
The electronic excitation spectra of undoped, and potassium as well as calcium doped phenantrene-type hydrocarbons have been investigated using electron energy-loss spectroscopy (EELS) in transmission. In the undoped materials, the lowest…
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…
In the preceding paper, we assembled the theoretical components necessary for a unified framework of singlet fission, a type of multiexciton generation producing two triplet excitons from one singlet exciton. In this paper, we apply our…
The mechanisms underlying coherent and thermally activated singlet exciton fission in pi-stacked acene crystals are clarified based on quantum dynamics simulations parameterized against a highly correlated description of the electronic…
The fission of singlet excitons into triplet pairs in organic materials holds great technological promise, but the rational application of this phenomenon is hampered by a lack of understanding of its complex photophysics. Here, we use the…
Organic semiconductor crystals stand out as an efficient, cheap and diverse platform for realising optoelectronic applications. The optical response of these crystals is governed by a rich tapestry of exciton physics. So far, little is…
Non-radiative exciton relaxation processes are critical for energy transduction efficiencies in optoelectronic materials, but how these processes are connected to the underlying crystal structure and its associated electron, exciton, and…
We revisit low-temperature optical spectra of transition-metal dichalcogenide monolayers and point to a possible crystallization of electrons (or holes) at low to moderate charge densities. To calculate the excitonic spectra under such…
Precise understanding of the electronic structures of optically dark triplet-triplet multiexcitons that are the intermediate states in singlet fission (SF) continues to be a challenge. This is particularly true for intramolecular singlet…
The energy spectra and wavefunctions of bound excitons in important two-dimensional (2D) graphene derivatives, i.e., graphyne and graphane, are found to be strongly modified by quantum confinement, making them qualitatively different from…
We report quadruple configuration interaction calculations within the extended Pariser$-$Parr$-$Pople Hamiltonian on the excited states of aggregates of polyenes, crystalline acenes, and covalently linked dimers of acene molecules. We…
The excited state dynamics in organic semiconductors plays an important role for many processes associated with light absorption and emission. We have studied the momentum dependence of the lowest singlet excitons in tetracene molecular…