Related papers: Singlet Fission in Lycopene H-Aggregates
The importance of singlet fission as a fundamental process with a variety of implications in energy harvesting cannot be overstated. The challenge is in characterizing the energy states of these large singlet fission molecular aggregates…
We develop a new first-principles approach to predict and understand rates of singlet fission with an ab initio Green's-function formalism based on many-body perturbation theory. Starting with singlet and triplet excitons computed from a GW…
We describe our dynamical simulations of the excited states of the carotenoid, neurosporene, following its photoexcitation into the 'bright' (nominally $1^1B_u^+$) state. We employ the adaptive tDMRG method on the UV model of…
A theory is developed to describe the singlet dark state (usually labeled S1 or 2Ag) of polyenes and carotenoids. The theory assumes that in principle this state is a linear combination of a singlet triplet-pair and an odd-parity…
Experimental investigations of magnetic field dependent kinetics of singlet fission (SF)processes in some organic semiconductors [i.e. splitting of excited singlet (S_1) state into a triplet exciton pair] have revealed the important…
An explanation is provided for the ultrafast photo-excited electron dynamics in low-spin Ruthenium (II) organic complexes. The experimentally-observed singlet to triplet decay in the metal-to-ligand charge-transfer (MLCT) states contradicts…
The coherent two-dimensional (2D) electronic spectra with respect to the singlet fission (SF) process in organic molecular aggregates are simulated by the Davydov ansatz combined with the Frenkel-Dirac time-dependent variational algorithm.…
Singlet exciton fission (SEF) is initiated by ultrafast internal conversion of a singlet exciton into a correlated triplet pair (TT)1. The `reaction coordinates' for ultrafast SEF even in archetypal systems such as pentacene thin film…
The photoinduced excited-state dynamics of the keto and enol forms of cytosine is investigated using ab initio surface hopping in order to understand the outcome of molecular beam femtosecond pump-probe photoionization spectroscopy…
Singlet fission, an exciton multiplication process in organic semiconductors which converts one singlet exciton into two triplet excitons is a promising way to reduce thermalization losses in conventional solar cells. One way to harvest…
As is well known, the ground-state symmetry group of the water dimer switches from its equilibrium $C_{s}$-character to $C_{2h}$-character as the distance between the two oxygen atoms of the dimer decreases below $R_{\rm O-O}\sim 2.5$…
We develop a powerful tree tensor network states method that is capable of simulating exciton-phonon quantum dynamics of larger molecular complexes and open quantum systems with multiple bosonic environments. We interface this method with…
While isolated quantum systems generally thermalize after long-time evolution, there are several exceptions defying thermalization. A notable mechanism of such nonergodicity is the Hilbert space fragmentation (HSF), where the Hamiltonian…
Effective models of hard-core hole pair bosons and triplets are derived from the t-J model in ladders and on the square lattice by performing a change from site to dimer basis. The Hilbert space is truncated by projecting out…
Singlet fission (SF) is a multi-exciton generation process that could be harnessed to improve the efficiency of photovoltaic devices. Experimentally, systems derived from the pentacene molecule have been shown to exhibit ultrafast SF with…
There are two types of two-photon transitions in molecular aggregates, that is, non-local excitations of two monomers and local double excitations to some higher excited intra-monomer electronic state. As a consequence of the inter-monomer…
A self consistent field theory for compressible polymer mixtures is developed by introducing elements of classical density functional theory into the framework of the Helfand theory. It is then applied to study free surfaces of binary (A,B)…
Singlet fission, a process that splits a singlet exciton into a biexciton, has promise in quantum information. We report time-resolved electron paramagnetic resonance measurements on a molecule, TIPS-BP1$'$, designed to exhibit strongly…
Carrier multiplication by singlet exciton fission enhances photovoltaic conversion efficiencies in organic solids. This decay of one singlet exciton into two triplet states promises to overcome the Shockley-Queisser limit as up to two…
We experimentally show that the rate of singlet fission in tetracene films has a superlinear dependence on the density of photo-excited singlet excitons with ultrafast transient absorption spectroscopy. The spectrotemporal features of…