Related papers: Endothermic singlet fission does not proceed via a…
A very promising approach to obtain efficient upconversion of light is the use of triplet-triplet annihilation of excitations in molecular systems. In real materials, besides upconversion, many other physical processes take place -…
Understanding the thermodynamics of the duplication process is a fundamental step towards a comprehensive physical theory of biological systems. However, the immense complexity of real cells obscures the fundamental tensions between energy…
We study two-electron states confined in two coupled quantum dots formed by a short-range potential in a two-dimensional topological insulator. It is shown that there is a fairly wide range of the system parameters, where the ground state…
Excitons are composite bosons that can feature spin singlet and triplet states. In usual semiconductors, without an additional spin-flip mechanism, triplet excitons are extremely inefficient optical emitters. Large spin-orbit coupling in…
When electron-hole pairs are excited in a semiconductor, it is a priori not clear if they form a fermionic plasma of unbound particles or a bosonic exciton gas. Usually, the exciton phase is associated with low temperatures. In atomically…
Excitons, electron-hole pairs bound by the Coulomb potential, are fundamental quasiparticles of coherent light-matter interaction energizing processes from photosynthesis to optoelectronics. Excitons are observed in semiconductors, and…
There is an enormous potential in applying conjugated polymers in novel organic opto-electronic devices such as light emitting diodes and solar cells. Although prototypes and first products exist, a comprehensive understanding of the…
The nature and extent of the spin-entanglement in the triplet-triplet biexciton with total spin zero in correlated-electron $\pi$-conjugated systems continues to be an enigma. Differences in the ultrafast transient absorption spectra of…
Entangled photon pairs are key to many novel applications in quantum technologies. Semiconductor quantum dots can be used as sources of on-demand, highly entangled photons. The fidelity to a fixed maximally entangled state is limited by the…
Exciton-polaritons are quasiparticles with mixed photon and exciton character that demonstrate rich quantum phenomena, novel optoelectronic devices and the potential to modify chemical properties of materials. Organic semiconductors are of…
Organic bulk-heterojunctions (BHJ) and solar cells containing the trimetallic nitride endohedral fullerene 1-[3-(2-ethyl)hexoxy carbonyl]propyl-1-phenyl-Lu3N@C80 (Lu3N@C80-PCBEH) show an open circuit voltage (VOC) 0.3 V higher than similar…
We present an exciton/lattice model of the electronic dynamics of primary photoexcitations in a polymeric semiconductor heterojunction which includes both polymer pi-stacking, energetic disorder, and phonon relaxation. Results from our…
We leverage 3D numerical simulations to study phase change materials (PCMs) cells under the effect of buoyancy forces. The solid PCM is heated from a source boundary, triggering melting. The source features multiple solid fins that protrude…
Electrons and holes residing on the opposing sides of an insulating barrier and experiencing an attractive Coulomb interaction can spontaneously form a coherent state known as an indirect exciton condensate. We study a trilayer system where…
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…
We estimate the energy distribution of positrons produced in the interaction of ultra-relativistic electrons with a high-intensity laser beam. The underlying trident process is factorized on the probabilistic level. That is, we deploy a…
Structurally well-defined TIPS-acetylene substituted tetracene (TIPS BT1') and pentacene (TIPS BP1') dimers utilizing a [2.2.1] bicyclic norbornyl bridge have been studied -primarily using time-resolved spectroscopic methods - to uncover…
Metal-insulator transitions (MIT) occurring in non-adiabatic conditions can evolve through high-energy intermediate states that are difficult to observe and control via static methods. By monitoring the out-of-equilibrium structural…
We demonstrate the conversion of cold Cs_{2} molecules initially distributed over several vibrational levels of the lowest triplet state a^{3}\Sigma_{u}^{+} into the singlet ground state X^{1}\Sigma_{g}^{+}. This conversion is realized by a…
Singlet fission, a phenomenon in which a singlet exciton is converted to two triplet excitons, is sensitive to vibrations that perturb couplings between electronic states (i.e., Peierls vibrations). In singlet fission models larger than…