Related papers: Chain Conformation and Exciton Delocalization in a…
Conformations of a single semiflexible polymer chain dissolved in a low molecular weight liquid crystalline solvents (nematogens) are examined by using a mean field theory. We takes into account a stiffness and partial orientational…
We have identified excitonic confinement in one-dimensional molecular chains (i.e. polyacetylene and H$_2$) as the main driving force for the saturation of the chain polarizability as a function of the number of molecular units. This…
We examine the phase transition of polymer adsorption as well as the underlying kinetics of polymer binding from dilute solutions on a structureless solid surface. The emphasis is put on the properties of regular multiblock copolymers,…
Interlayer excitons in two dimensional semiconductor heterostructures show suppressed electron-hole overlap resulting in longer radiative lifetimes as compared to intralyer excitons. Such tightly bound interlayer excitons are relevant for…
Conjugated polymers can be reversibly doped by electrochemical means. This doping introduces new sub-bandgap optical absorption bands in the polymer while decreasing the bandgap absorption. To study this behavior, we have prepared an…
We show that electron-hole correlation can be used to tune interband and intraband optical transition rates in semiconductor nanostructures with at least one weakly confined direction. The valence-to-conduction band transition rate can be…
Quantum interference between one- and two-photon absorption pathways allows coherent control of interband transitions in unbiased bulk semiconductors; carrier population, carrier spin polarization, photocurrent injection, and spin current…
An excitonic method proper to study conjugated oligomers and polymers is described and its applicability tested on the ground state and first excited states of trans-polyacetylene, taken as a model. From the Pariser-Parr-Pople Hamiltonian,…
The packing geometry of macromolecules in complex mesophases is of key importance to self-organization in synthetic and biological soft materials. While approximate or heuristic models rely on often-untested assumptions about how flexible…
Forced detachment of a single polymer chain, strongly-adsorbed on a solid substrate, is investigated by two complementary methods: a coarse-grained analytical dynamical model, based on the Onsager stochastic equation, and Molecular Dynamics…
Exciton-polaritons in organic materials are hybrid states that result from the strong interaction of photons and the bound excitons that these materials host. Organic polaritons hold great interest for optoelectronic applications, however…
Conjugated polymers are complex multi-chromophore systems, with emission properties strongly dependent on the electronic energy transfer through active sub-units. Although the packing of the conjugated chains in the solid state is known to…
We report direct evidence for macroscopic coherence in a condensate of dark dipolar excitons in coupled quantum wells and show that its formation follows a non-equilibrium, driven-dissipative mechanism. The condensation transition is…
We investigate the dynamics of the exciton formation and relaxation on a picosecond time scale following a pulsed photoexcitation of a semiconductor. The study is conducted in the framework of the density matrix theory complemented with the…
The exciton relaxation dynamics of photoexcited electronic states in poly($p$-phenylenevinylene) (PPV) are theoretically investigated within a coarse-grained model, in which both the exciton and nuclear degrees of freedom are treated…
Two-dimensional semiconducting systems, such as quantum wells and transition metal dichalcogenides, are the foundations to investigate low dimensional light-matter interactions. To date, the study of elementary photoexcitation, namely the…
Heterostructures of layered transition metal dichalcogenides (TMDs) host long-lived, tunable excitons, making them intriguing candidates for material-based quantum information applications. Light absorption in these systems induces a…
We have performed detailed photoluminescence (PL) and absorption spectroscopy on the same single self-assembled quantum dot in a charge-tunable device. The transition from neutral to charged exciton in the PL occurs at a more negative…
When injected through a contraction, high molecular weight polymer solutions exhibit a sharp increase of apparent viscosity which originates from stretching polymer chains above a critical extension rate. This chain stretching can also…
We show that the structural properties and phase behavior of a self-avoiding polymer chain on adhesive substrate, subject to pulling at the chain end, can be obtained by means of a Grand Canonical Ensemble (GCE) approach. We derive…