Topic
Bipolaron
About: Bipolaron is a research topic. Over the lifetime, 1335 publications have been published within this topic receiving 29154 citations. The topic is also known as: bipolarons.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this paper, an in situ study of the absorption spectra of poly(p-phenylene) films during the electrochemical doping with AsF 6 has been carried out.
Abstract: Poly( p -phenylene) films with a conductivity of ca . 100 S/cm are synthesized by a new method of electrical oxidation of benzene using the composite electrolytes of CuCl 2 /LiAsF 6 . An in situ study of the absorption spectra of the poly( p -phenylene) films during the electrochemical doping with AsF 6 has been carried out. From the absorption spectrum of undoped state, we find a strong absorption peak at ca . 3.4 eV which is associated with the transition from ground-state to excited-state. The remarkable changes of the absorption spectra below the photon energy of 3.0 eV are observed, which are related to the polaron and/or bipolaron states of this polymer. The electrochemical n -type doping is also demonstrated.
27 citations
TL;DR: In this article, the bound states of two electrons in the adiabatic Holstein-Hubbard model are studied numerically in one and two dimensions from the anticontinuous limit.
27 citations
TL;DR: In this paper, the properties of poly(isothianaphthene) as a function of doping potential and electronic states are discussed in detail, and the band gap is evaluated to be 1.0 eV and the evolution of localized states with electrochemical doping.
Abstract: Electrochemical, optical, and magnetic properties of poly(isothianaphthene) as a function of doping potential and electronic states, are discussed in detail. The band gap of poly(isothianaphthene) has been evaluated to be 1.0 eV and the evolution of localized states is evidenced by the spectral change with electrochemical doping. The magnetic susceptibility evaluated from electron spin resonance measurement has exhibited the highest value at a doping potential of 3.5 V vs Li/Li+. These results are interpreted in terms of the polaron and/or bipolaron models. The electronic band structure of poly(isothianaphthene) has been determined. The top of the valence band of poly(isothianaphthene) is located at an energy state higher than that of polythiophene by about 0.5 eV. On the other hand, the bottom of the conduction band of poly(isothianaphthene) is located at an energy state lower than that of polythiophene by about 0.6 eV, suggesting successful electrochemical n-type doping.
27 citations
TL;DR: In this article, the gap between bonding and antibonding was shown to be closed at the highest doping level and a metallic state was observed at the lowest doping level, consistent with the bipolaron model showing two defect states in the gap.
Abstract: Electron-energy-loss spectroscopy has been used to investigate the electronic structure of Li-doped polyparaphenylene. For low doping concentration the results are consistent with the bipolaron model showing two defect states in the gap. At the highest doping level, the gap between bonding and antibonding $\ensuremath{\pi}$ electrons is closed and a metallic state is observed.
27 citations
TL;DR: In this article, a variational numerical method was used to compute the time evolution of the Holstein-Hubbard bipolaron from its ground state when at t = 0 the constant electric field is switched on.
Abstract: Using a variational numerical method we compute the time-evolution of the Holstein-Hubbard bipolaron from its ground state when at t=0 the constant electric field is switched on. The system is evolved taking into account full quantum effects until it reaches a quasi-stationary state. In the zero-field limit the current shows Bloch oscillations characteristic for the adiabatic regime where the electric field causes the bipolaron to evolve along the quasiparticle band. Bipolaron remains bound and the net current remains zero in this regime. At larger electric fields the system enters the dissipative regime with a finite steady-state current. Concomitantly, the bipolaron dissociates into two separate polarons. By examining different parameter regimes we show that the appearance of a finite steady-state current is inevitably followed by the dissociation of the bipolaron.
27 citations