We present a theory for spin-polarized transport through a generic organic polymer connected to ferromagnetic leads with arbitrary angle theta between their magnetization directions, taking into account the polaron and bipolaron states as effective charge and spin carriers. Within a diffusive description of polaron-bipolaron transport including polaron-bipolaron conversion, we find that the bipolaron density depends on the angle theta. This is remarkable, given the fact that bipolarons are spinless quasiparticles, and opens a new way to probe spin accumulation in organic polymers.
We demonstrate that nuclear spin fluctuations lead to the electric current noise in the mesoscopic samples of organic semiconductors showing the pronounced magnetoresistance in weak fields. For the bipolaron and electron-hole mechanisms of organic magnetoresistance, the current noise spectrum consists of the high frequency peak related to the nuclear spin precession in the Knight field of the charge carriers and the low frequency peak related to the nuclear spin relaxation. The shape of the spectrum depends on the external magnetic and radiofrequency fields, which allows one to prove the role …
Controllable topological phase transitions are appealing as they allow for tunable single particle electronic properties. Here, by using state-of-the-art manybody perturbation theory techniques, we show that the topological $Z_2$ phase transition occurring in the single particle spectrum of the recently synthetized ethynylene bridged polyacene polymers is accompanied by a topological excitonic phase transition: the band inversion in the non-trivial phase yields real-space exciton wave functions in which electrons and holes exchange orbital characters with respect to the trivial phase. The topo…
We demonstrate an emulsion-polymerisation technique to embed dibenzoterrylene-doped anthracene nanocrystals in polymethyl methacrylate (PMMA) nanocapsules. The nanocapsules require no further protection after fabrication and are resistant to sublimation compared to unprotected anthracene. The room temperature emission from single dibenzoterrylene molecules is stable and when cooled to cryogenic temperatures we see no change in their excellent optical properties compared to existing growth methods. These now robust nanocapsules have potential for surface functionalisation and integration into n…
Natural photosynthetic photonic nanostructures can show sophisticated light matter-interactions including enhanced light absorption by slow light even for highly pigmented systems. Beyond fundamental biology aspects these natural nanostructures are very attractive as blueprints for advanced photonic devices. But the soft-matter biomimetic implementations of such nanostructures is challenging due to the low refractive index contrast of most organic photonic structures. Excitonic organic material with near zero index (NZI) optical properties allow overcoming these bottlenecks. Here we demonstrat…
Conjugated polymer-based organic electrochemical transistors (OECTs) are being studied for applications ranging from biochemical sensing to neural interfaces. While new conjugated polymers are being developed that can interface digital electronics with the aqueous chemistry of life, the vast majority of high-performance, high-mobility organic transistor materials developed over the past decades are extremely poor at taking up biologically-relevant ions. Here we incorporate an ion exchange gel into an OECT, demonstrating that this structure is capable of taking up biologically-relevant ions fro…
Metal nanostructures are key elements in nanooptics owing to their strong resonant interaction with light through local plasmonic charge oscillations. Their ability to shape light at the nanoscale have made them important across a multitude of areas, including biosensing, energy conversion and ultrathin flat metaoptics. Yet another dimension of avenues is foreseen for dynamic nanoantennas, ranging from tuneable metalenses for miniaturized medical devices to adaptable windows that control radiation flows in and out of buildings. However, enabling nano-optical antennas to be dynamically controll…
The functionalization of semiconducting single-walled carbon nanotubes (SWNTs) with sp$^{3}$ defects that act as luminescent exciton traps is a powerful means to enhance their photoluminescence quantum yield (PLQY) and to add optical properties. However, the synthetic methods employed to introduce these defects are so far limited to aqueous dispersions of surfactant-coated SWNTs, often with short tube lengths, residual metallic nanotubes and poor film formation properties. In contrast to that, dispersions of polymer-wrapped SWNTs in organic solvents feature unrivaled purity, higher PLQY and ar…
Recently a variety of $π$-conjugated polymers have been developed and essayed for a number of applications such as organic light-emitting diodes, organic field-effect transistors, organic photovoltaics, and sensors. Is central for these applications the semiconductor character of the pure materials, which can turn into metallic conductivity by local oxydation or reduction. Many very recent experiments show two characteristic peaks in the UV-Vis excitation spectra of the conjugated polymers of interest, both lying in the gap between the energies of the bonding $π$ and antibonding $π^*$ bands an…
For Holstein model with Rashba spin-orbit coupling (SOC) we establish the nonlinear Schrödinger equations and obtain exact soliton solution analytically. It is found that the soliton is spin polarized determined both by the SOC and the electron-phonon (e-ph) interaction. The soliton can be used to describe the spin transport or spin current in organic semiconductors.
We have presented a consistent electronic transport framework for the two-dimensional extended Holstein's organic molecular-crystal based upon complete quantum-mechanical treatment through the non-equilibrium Green's function (NEGF) formalism and corresponding one-to-one semi-classical framework based upon Boltzmann transport theory for the narrow-bandwidth electronic energy organic semiconductor crystal material and device. In this process, we have formulated electronic self-energy interaction with acoustic and polar optical phonon mode with one phonon and two phonon interactions through Feyn…
