Poly(3-hexylthiophene) revisited – Influence of film deposition on the electrochemical behaviour and energy levels

Bruchlos, Kirsten; Trefz, Daniel; Hamidi-Sakr, Amer; Brinkmann, Martin; Heınze, Jürgen; Ruff, Adrian; Ludwigs, Sabine

doi:10.1016/j.electacta.2018.02.126

Cited by 35 publications

(56 citation statements)

References 88 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The investigation of basic electrochemical properties through cyclic voltammetry of spherulitic P3HT further confirmed the high degree of order in the solvent vapor annealed films . Conversely, a strong influence of the morphology—and the molecular order in particular—on the electrochemical properties were shown.…”

Section: Polymer Spherulites In Organic Electronicsmentioning

confidence: 66%

“…In addition, the onset potential of the oxidation wave (cf. Figure ) shifts from 0.0 V in the pristine spin coated film to +0.07 V in the solvent vapor annealed spherulitic film . Assuming a formal potential of −5.1 eV of the Fc/Fc + redox couple in the Fermi scale, these values yield HOMO energies of −5.10 and −5.17 eV, respectively, indicating a lower HOMO level in consequence of a higher order in the spherulitic film.…”

Section: Polymer Spherulites In Organic Electronicsmentioning

confidence: 96%

Section: Spherulites In Semiconducting Semicrystalline Polymer Filmsmentioning

confidence: 99%

Section: Polymer Spherulites In Organic Electronicsmentioning

confidence: 99%

“…The morphology is highly determined by the processing method, which is commonly melt processing. In conjugated polymers this structure‐property relation extends to functional, that is, optical and electronic properties . In this class of polymers, the morphology further determines the performance of devices such as organic field‐effect transistors, organic photovoltaics, and thermoelectric generators.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Semiconducting Polymer Spherulites—From Fundamentals to Polymer Electronics

Dingler

Dirnberger

Ludwigs

2018

Macromol. Rapid Commun.

Self Cite

View full text Add to dashboard Cite

structures have to be highly regularexamples are given in Figure 1. This includes regular sequences of repeat units, high regioregularity, and defined tacticity (isotactic or syndiotactic). In addition, strong intermolecular interactions such as hydrogen bonds (e.g., in polyamides) or π-π stacking (e.g., in conjugated polymers) can strongly favor crystallization. To get control over the crystallinity of semicrystalline polymers, numerous efforts have been made. For crystallization in general, thermodynamic as well as kinetic aspects must be taken into account. The structure formation of semicrystalline polymers, however, is determined by kinetics rather than equilibrium thermodynamics. This is particularly prominent for the processing from solution, where the rapid solvent removal determines the fast crystallization kinetics. This implies that the time given for crystallization is crucial and that the resulting morphology has a strong dependence on the history imposed by processing. Thus a precise control of crystallization conditions such as temperature and time is required to obtain defined morphologies.This feature article first gives a very short overview of classical crystallization theory including nucleation and growth, where the focus should be on spherulite growth. In the second part, this article will extend toward semicrystalline polymers with additional semiconducting properties that were crystallized in spherulitic morphologies. Spherulites are the most common superstructure in semicrystalline polymers that are also formed during classical processing like injection molding. As the spherulite size affects mechanical properties of the polymeric material such as tensile strength and strain at failure, it is important to be able to control spherulite growth. The growth of spherulites of classical semicrystalline polymers such as PP during processing can, for instance, be controlled with nucleating agents. While spherulites are aimed to be very small in this case, for semiconducting semicrystalline polymers the growth of large spherulites is advantageous. The known radial growth and the defined orientation of lamellae and crystal axes allows for direction dependent measurements of charge carrier mobility or conductivity. Therefore charge transport anisotropy can be studied and structureproperty relations established. Solvent vapor annealing as the most suitable technique to induce the desired crystallization into spherulites is introduced in this article, and the resulting anisotropic optical and electronic properties are presented. The high degree of orientation and improved crystallinity in spherulites also improves the overall charge transport properties. To do so, Conducting PolymersThe control of the morphology of semiconducting semicrystalline polymers is crucial to the performance of various electronic devices. Among other superstructures in semicrystalline polymers, spherulites stand out for various reasons. They are highly ordered, relatively easy to grow, and their underlying molecular structure...

show abstract

Section: Polymer Spherulites In Organic Electronicsmentioning

confidence: 66%

Section: Polymer Spherulites In Organic Electronicsmentioning

confidence: 96%

Section: Spherulites In Semiconducting Semicrystalline Polymer Filmsmentioning

confidence: 99%

Section: Polymer Spherulites In Organic Electronicsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Semiconducting Polymer Spherulites—From Fundamentals to Polymer Electronics

Dingler

Dirnberger

Ludwigs

2018

Macromol. Rapid Commun.

Self Cite

View full text Add to dashboard Cite

show abstract

Preferential Location of Dopants in the Amorphous Phase of Oriented Regioregular Poly(3‐hexylthiophene‐2,5‐diyl) Films Helps Reach Charge Conductivities of 3000 S cm⁻¹

Zhong

Untilova

Müller

et al. 2022

Adv Funct Materials

Self Cite

View full text Add to dashboard Cite

Doping polymer semiconductors is a central topic in plastic electronics and especially in the design of novel thermoelectric (TE) materials. In this contribution, it has been demonstrated that doping of oriented semicrystalline P3HT thin films with the dopant tris(4-bromophenyl)ammoniumyl hexachloroantimonate), known as magic blue (MB), helps reach charge conductivities of 3000 S cm −1 and TE power factors of 170 ± 30 μW mK −2 along the polymer chain direction. A combination of transmission electron microscopy, polarized optical absorption spectroscopy, Rutherford backscattering, and TE property measurements helps clarify the conditions necessary to achieve such high charge conductivities. A comparative study with different dopants demonstrates that the doping mechanism is intimately related to the semicrystalline structure of the polymer and whether crystalline, amorphous or both phases are doped. The highest charge mobilities are observed when the dopant MB is preferentially located in the amorphous phase of P3HT, leaving the structure of P3HT nanocrystals almost unaltered. In this case, the P3HT nanocrystals are doped from their interface with the surrounding amorphous phase. These results indicate that doping preferentially the amorphous phase of semicrystalline polymer semiconductors is an effective strategy to reduce polaron localization, enhance charge mobilities, and improve TE power factors.

show abstract

Chemical Doping of Conjugated Polymers with the Strong Oxidant Magic Blue

Hofmann

Kroon

Zokaei

et al. 2020

Adv Elect Materials

Self Cite

View full text Add to dashboard Cite

The opto-electronic as well as the mechanical properties of semiconducting polymers depend strongly on the charge-carrier density, which can be tuned chemically or electrochemically, a process which is referred to as doping. Hence, doping is a powerful tool to optimize the performance of organic electronic devices, such as transistors, solar cells and organic light-emitting diodes (OLEDs), [1,5] as well as of organic thermoelectric materials. [6][7][8] Further, in case of electrochemical transistors and light-emitting electrochemical cells, modulation of the charge-carrier density is essential to the operation of these devices. [9,10] One way to introduce charges is via redox doping, also referred to as molecular doping, which involves an electron transfer between the semiconducting polymer and a small molecule, the socalled redox dopant. In case of p-doping a positive energetic offset between the electron affinity (EA) of the small-molecular dopant and the ionization energy (IE) of the semiconducting polymer is advantageous, i.e., EA dopant > IE polymer . Depending on the relative position of the energy levels one or even two electrons can be transferred from the polymer backbone to a dopant molecule. [11] A broad variety of p-and n-type polymer-dopant couples have been studied. The most common p-type redox dopant is 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ), [12,13] which shows an electron affinity of EA ≈ 5.2 eV and readily oxidizes polymers such as poly(3-hexylthiophene) (P3HT; IE ≈ 5.1 eV) [14][15][16][17][18][19] and thiophene-thienothiophene copolymers (PBTTT; IE ≈ 5.2 eV). [20,21] Many other conjugated polymers such as, for example, high-mobility donor-acceptor polymers have an IE of more than 5.3 eV and can therefore not be doped with F4TCNQ. At the same time, doping of high mobility polymers is of special interest in the field of organic thermoelectrics, because the use of such polymers may allow to increase the thermoelectric power factor, which scales with the electrical conductivity and hence charge-carrier mobility. [22,23] There are only few examples of dopants with a high electron affinity including 1,3,4,5,7,8-hexafluoro-tetracyano-naphthoquinodimethane (F6TCNNQ) (EA ≈ 5.3 eV), [11,24] hexacyano-trimethylene-cyclopropane (EA ≈ 5.9 eV) [24] and its derivatives, [25] and molybdenum dithiolene complexes such as Mo(tfd-COCF 3 ) 3 Molecular doping of organic semiconductors is a powerful tool for the optimization of organic electronic devices and organic thermoelectric materials. However, there are few redox dopants that have a sufficiently high electron affinity to allow the doping of conjugated polymers with an ionization energy of more than 5.3 eV. Here, p-doping of a broad palette of conjugated polymers with high ionization energies is achieved by using the strong oxidant tris(4bromophenyl)ammoniumyl hexachloroantimonate (Magic Blue). In particular diketopyrrolopyrrole (DPP)-based copolymers reach a conductivity of up to 100 S cm −1 and a thermoelectric power factor of 10 µW m −...

show abstract

Poly(3-hexylthiophene) revisited – Influence of film deposition on the electrochemical behaviour and energy levels

Cited by 35 publications

References 88 publications

Semiconducting Polymer Spherulites—From Fundamentals to Polymer Electronics

Semiconducting Polymer Spherulites—From Fundamentals to Polymer Electronics

Preferential Location of Dopants in the Amorphous Phase of Oriented Regioregular Poly(3‐hexylthiophene‐2,5‐diyl) Films Helps Reach Charge Conductivities of 3000 S cm⁻¹

Chemical Doping of Conjugated Polymers with the Strong Oxidant Magic Blue

Contact Info

Product

Resources

About

Poly(3-hexylthiophene) revisited – Influence of film deposition on the electrochemical behaviour and energy levels

Cited by 35 publications

References 88 publications

Semiconducting Polymer Spherulites—From Fundamentals to Polymer Electronics

Semiconducting Polymer Spherulites—From Fundamentals to Polymer Electronics

Preferential Location of Dopants in the Amorphous Phase of Oriented Regioregular Poly(3‐hexylthiophene‐2,5‐diyl) Films Helps Reach Charge Conductivities of 3000 S cm−1

Chemical Doping of Conjugated Polymers with the Strong Oxidant Magic Blue

Contact Info

Product

Resources

About

Preferential Location of Dopants in the Amorphous Phase of Oriented Regioregular Poly(3‐hexylthiophene‐2,5‐diyl) Films Helps Reach Charge Conductivities of 3000 S cm⁻¹