Charge Carrier Scattering in Polymers: A New Neutral Coupled Soliton Channel

Abstract

The dynamical scattering of two oppositely charged bipolarons in non-degenerate organic semiconducting lattices is numerically investigated in the framework of a one-dimensional tight-biding–Hubbard model that includes lattice relaxation. Our findings show that it is possible for the bipolaron pair to merge into a state composed of a confined soliton-antisoliton pair, which is characterized by the appearance of states within less than 0.1 eV from the Fermi level. This compound is in a narrow analogy to a meson confining a quark-antiquark pair. Interestingly, solitons are quasi-particles theoretically predicted to arise only in polymer lattices with degenerate ground state: in the general case of non-degenerate ground state polymers, isolated solitons are not allowed.

Probing the nature of charge carriers in one-dimensional conjugated polymers: a review of the theoretical models, experimental trends, and thermoelectric applications

“…However, the intensity of polarons increased with the electrochemical oxidation potentials up to 0.0 V, and drastically decreased to the minimum as the oxidation potential reached +0.7 V; this phenomenon can be attributed to the combination of the polarons to form the spinless bipolarons, accompanied by the abrupt increase in line widths from 0.0 V to +0.7 V. Moreover, bipolarons can be transformed into quasi-particles of different functions in the lattice of non-degenerate conjugated polymers, e.g., a coupled confined spinless soliton-antisoliton pair upon scattering. 117 State-of-the-art strategies for improving the doping efficiency include tuning the ionization potential of dopants or polymers, manipulating the distance between dopants and charge carriers, and designing the molecular and crystallization structures of the host. [118][119][120] For example, mutual electrical doping has been achieved by using a p-doped conjugated polymer with low ionization potential, bithiophene-co-thiophene [P(g 4 2T-T)], and a n-doped conjugated polymer with high electron affinity, poly(benzimidazophenanthroline) (BBL), to dope each other.…”

Conductive Polymers for Flexible and Stretchable Organic Optoelectronic Applications

“…These delocalized charge carriers on the polymer chains facilitate the electronic conductivity. Hence, the conductivity of CPs is attributed to the charge carriers, i.e., solitons, polarons, and bipolarons …”

“…Hence, the conductivity of CPs is attributed to the charge carriers, i.e., solitons, polarons, and bipolarons. 48 2.2. Electrical Conductivity and Mechanical Property of CPs.…”

Graphene-Substrate Effects on Characteristics of Weak-Coupling Bound Magnetopolaron

“…It is expected to replace silicon as an important raw material for the next generation of semiconductor materials. As such, graphene has been an area of intense focus in solid-state research in recent years [1][2][3][4][5][6][7][8][9][10]15].…”