Themed collection Celebrating 50 years of Professor Fred Wudl’s contributions to the field of organic semiconductors

Guest editors Qichun Zhang, Dmitrii Perepichka and Zhenan Bao introduce this Journal of Materials Chemistry C themed issue on organic semiconductors, in celebration of Professor Fred Wudl's fifty-year contribution to the field.

Case studies of minor structural variations highlight the fundamental relationship between structure and function to offer design rules with which to develop the next generation of organic electronic materials.

Recent development of one-dimensional conjugated polymer nanomaterials for flexible and stretchable electronics and their perspectives are introduced in this study.

Various strategies to chemically modify acenes for n-channel OFETs are discussed. Such strategies could also be useful for design of efficient n-type organic semiconductors based on other π-systems.

A review to explore how to design fullerenes and their derivatives as semiconductors in field-effect transistors.

Both broadband and narrowband organic photodetectors can be realized due to the easily tunable optical/electronic properties of organic semiconductors.

The recent progress on the methods to prepare donor (D)–acceptor (A) co-crystals and their potential applications in OFETs has been reviewed.

Deep-blue thermally activated delayed fluorescence materials based on dibenzo-fused phosphacycles are developed.

A 0D perovskite-related material Cs₃Fe₂Br₉ is shown to have a low bandgap of 1.65 eV and exhibit antiferromagnetic behaviour.

Solution-processed polymer PDs with a spectral response ranging from 350 nm to 2500 nm.

A novel quinone bridged large azaacene exhibits an electron mobility of 0.22 cm² V⁻¹ s⁻¹ through molecular stacking structure engineering.

A series of electron deficient small molecules using fused anthraquinone and naphthalimide conjugated backbone with different alkyl chain length with lower LUMO for n-channel organic thin film transistor.

We have investigated spin related processes in fullerene C₆₀ devices using a several experimental techniques, which include magnetic field effect of photocurrent and electroluminescence in C₆₀-based diodes; spin polarized carrier injection in C₆₀-based spin-valves; and pure spin current generation in NiFe/C₆₀/Pt trilayer devices.

Molecular orientation and supramolecular structure of tetrathiafulvalene derivative on graphite can be controlled by the change of deposition solvent, as revealed by scanning probe microscopy study.

4,5-Diazafluorene co-oligomers combine improved electron affinity with strong fluorescence and can be used as electron transporting and light-emitting materials, as well as fluorescent sensors for Hg²⁺ cations.

In studying the formation and thermally activated cycloreversion of oxidized rubrene to pristine rubrene, we observed an irreversible, second stage oxidized product. Understanding the formation of the irreversible adduct will help one design more chemically robust rubrene derivatives.

With enhanced electrical properties, TPAPOPPA can deliver decent efficiencies in non-doped, doped, single-layer, yellow and white OLEDs.

Conjugated polyelectrolytes (CPEs) have been applied as sensors for various small molecules and ions including biologically important ions.

Functionalization of benzo[1,2-b:4,5-b′]dithiophenes (BDTs) with thiacycles to selectively tune the packing, molecular orientation and semiconducting properties is systematically studied.

A facile one-pot, microwave-assisted synthesis of novel functionalized arylenedioxythiophenes as promising building blocks for conjugated polymers with tuneable electronic properties is presented.

New 5,7-diazapentacene-based materials have been made by means of a Friedländer reaction, which could be promising candidates for optoelectronic applications.

Subtle changes in the choice of the chalcogen atom in benzochalcogenadiazole ‘small molecules’ can lead to a marked difference in the PCE of bulk heterojunction organic solar cells.

A new dopant free stable HTM using anthanthrone dye has been reported with 11.5% efficiency.

Pd(PPh₃)₂Cl groups hinder aggregation and afford promising solid-state NLO properties.

Chrysene and [1]benzothieno[3,2-b][1]benzothiophene possess a similar electronic structure, and chrysene is expected to have better semiconductor device performance than BTBT, owing to the stronger electronic couplings.

New robust n-type light emitters are developed from AIE-active silole derivatives, enabling the OLEDs to operate efficiently in a simplified configuration.

The first fluorinated copolymers based on benzobisthiadiazole (BBT) and its derivatives are newly synthesized, which show an inversion of charge carrier polarity and dramatic improvement of the mobility.

We study the impact of side chain placement on the thermal stability of solar cells in thiophene–thiazolothiazole polymers.

Extremely simple two-color all-TADF WOLEDs with a single-emissive-layer singe-host/dopant system provide a bright future for high-efficiency low-cost vacuum-deposited WOLEDs.

Polythiophene derivatives with ester side chains enable high open-circuit voltages in polymer–fullerene solar cells. The side chains affect the solubility, thermal properties, tendency to aggregate, and photovoltaic performance by modulating the morphology of the blends.

This study puts forth a new π-electron molecular scaffold containing two phenazine moieties connected by a four-membered ring. It exhibits interesting optical and electronic properties and sheds light on the role of the four-membered ring in conjugation.

We investigate mixtures of fullerenes and fullerene derivatives, the most commonly used electron accepting materials in organic solar cells, by using a combination of molecular dynamics and density functional theory methods.

A 4H-1,2,6-thiadiazine motif as a new acceptor for D–A conjugated polymers.