Double Doping of Semiconducting Polymers Using Ion‐Exchange with a Dianion

Abstract

The interactions between counterions and electronic carriers in electrically doped semiconducting polymers are important for delocalization of charge carriers, electronic conductivity, and thermal stability. The introduction of a dianions in semiconducting polymers leads to double doping where there is one counterion for two charge carriers. Double doping minimizes structural distortions, but changes the electrostatic interactions between the carriers and counterions. Polymeric ionic liquids (PIL) with croconate dianions are helpful to investigate the role of the counterion in p-type semiconducting polymers. PILs prevent diffusion of the cation into the semiconducting polymers during ion exchange. The redox-active croconate dianions undergo ion exchange with doped semiconducting polymers depending on their ionization energy. Croconate dianions are found to reduce doped films of poly(3-hexyl thiophene), but undergo ion exchange with a polythiophene with tetraethylene glycol side chains, P(g 4 2T-T), that has a lower ionization energy. The croconate dianion maintains crystalline order in P(g 4 2T-T) and leads to a lower activation energy for the electrical conductivity than PF 6 − counterions.The control of the doping level with croconate allows optimization of the thermoelectric performance of the semiconducting polymer. The thermal stability of the doped films of P(g 4 2T-T) is found to depend strongly on the nature of the counterion.

A review: advancing organic electronics through the lens of ionic liquids and polymerized ionic liquids

“…54). 234 The resulting P(g42T-T): croconate 2− possesses lower activation energy for electrical conductivity, maintaining the crystalline order in P(g42T-T).…”

Photoelectron Spectroscopy Confirms the Gas-Phase Stability of the C3O2– Anion

“…Oxocarbons play an important role in many chemical processes, such as the earth’s atmosphere and the interstellar medium. , In recent years, because of their applications in battery sciences and conducting polymers compounds, spectroscopic detection and characterization of this class of species and corresponding ions have attracted increasing interest. − Among the small oxocarbon molecules, carbon suboxide (C 3 O 2 ) has been studied both experimentally − and theoretically − to reveal its structure, ground-state potential energy surface, and spectroscopic properties. The ground state of C 3 O 2 has proven to be quasi-linear with a bent-to-linear barrier of only ∼18 cm –1 .…”