Themed collection Special issue in honour of Daoben Zhu

Guest editors Qichun Zhang, Wenping Hu, Thuc-Quyen Nguyen, Qibing Pei and Jia Zhu introduce this Journal of Materials Chemistry C issue in honour of Professor Daoben Zhu on the occasion of his 80th birthday.

Strategies for enhancing interfacial adhesion of organic semiconductors by adhesive layer introduction, adhesive group functionalization, adhesive integrated agent, and physical mixing, have shown promising applications in various fields.

For development of multifunctional smart devices, this perspective focuses on vertical transistors with short channels aided by nanotechnology.

Spintronic applications of OSSCs are discussed from the aspects of molecular structure, stacking structure, OSSC-based spintronic device fabrication, and multifunctional applications.

Recent issues toward ultrathin soft electronics are gradually focused on effective detection under complex environments. The promising strategies for long-term performance are summarized as a roadmap for design and fabrication.

The versatile synthetic side chain toolbox assists in tuning the OECT parameters by controlling material properties of organic mixed conductors. In this review we critically summarise and evaluate various side chains used throughout OECT materials.

This review focuses on the recent progress in the inclusion of a nonbenzenoid ring into the π-backbone of azaacenes, which can largely tune absorption, energy levels, and antiaromaticity, and produce exciting size-dependent properties.

Polycyclic aromatic hydrocarbons (PAHs) as a typical class of organic semiconductors demonstrate unique optical, electrical, magnetic and other interesting properties due to their extended conjugation and diverse structures.

In this review, we first summarize the general synthetic strategies towards stable open-shell organic conjugated materials, and then focus on their special aggregated states in OFETs, organic conductors, OLEDs and photoinduced radical materials.

We summarize the internal chemical mechanism, crystallization kinetics and future prospects of the MA⁰ healing process.

Featuring a combination of size-tunable emission wavelengths, high thermal stability, and low cytotoxicity, carbon quantum dots (CQDs) have opened up a new possibility for next-generation displays.

Detecting circularly polarized light is central to many advanced sensing technologies. We summarize the recent progress on the chiral materials developed for CPL detection and provide perspectives on strategies to improve the dissymmetry factors.

The use of solid additives in organic solar cells has drawn great attention owing to its great morphology-tuning ability. Here we review both organic and inorganic solid additives, which could provide useful guidance for the design of solid additives.

Single-molecule field-effect transistors (FETs) are the key building blocks of electronic circuits and a unique platform for studying physical mechanisms. Here, the designs, mechanisms and applications of single-molecule FETs are summarized.

This review summarizes recent progress in flexible transparent electrodes based on metallic micro–nano architectures, highlighting their applications in inverted, conventional and semi-transparent perovskite solar cells.

In this review, beside the formation mechanism and emission process of exciplexes, we mainly discuss the donor–acceptor contacting modes and luminescence properties, which are important to develop high-performance and multifunctional optoelectronics.

A soft template-assisted self-assembly (STAS) strategy was developed to grow large-area high-quality 2D molecular crystals on a water surface irrespective of the surface tension of the solvents.

A new low-bandgap D–A type non-fullerene acceptor is designed and synthesized, which is successfully applied in full-vacuum-deposited organic solar cells and realizes a PCE of 0.86%.

The intermolecular interactions of cocrystals can be controlled via selecting the donors and acceptors, and then the TPA properties can be selectively adjusted, promoting the development of TPA materials prepared via cocrystal engineering.

Through the combination of perylene diimide and triphenylamine moieties, a perovskite solar cell with DPT as the electronic transport material exhibited a PCE of 20.07%.

A systematic analysis of the phonon bands calculated using dispersion-corrected density functional theory for crystalline acenes reveals analogies between the phonons and classical oscillator models. Based on these, the evolution of the materials’ properties can be rationalised.

The single crystal field-effect transistor of 5,15-bis(triisopropylsilyl)ethynyltetrabenzoporphyrin exhibited better hole mobility than its metal complexes, with efficient charge transport through π–π stacking along tetrabenzoporphyrin units.

A macroscopic morphology regulation from rod- to sheet-shaped crystals with the same single structure was realized via building a two-dimensional packed network in plane for organic semiconductors.

Controllable photoluminescence anisotropy amplification was achieved in organic luminescent radical-doped microcrystals via exciton funneling.

The vibrational anomalies of pentacene molecules have been investigated in conjunction with the high-energy excitonic features. Self-trapped excitons have been distinguished from the others.

In (BEDT-TTF)₃[Cu₂(μ-C₂O₄)(C₂O₄)₂(CH₃OH)(H₂O)], BEDT-TTF stacks in β′′ mode and shows metallic conductivity. Hydrogen bonds between antiferromagnetic oxalate-bridged binuclear anions form a square lattice. No long range order observed to 2 K.

Thionation of a model perylene diimide has a significant impact on its self-assembly behaviour. This approach provides a facile route to simultaneously exert control over the mechanism, morphology and functionality of self-assembled PDI materials.

An amorphous carbon film formed by a pyrolysis photoresist as the bottom contact source/drain electrode of OFETs to improve the charge injection as well as the device performance.

GDYO/PVA self-assembled composite membrane as a separator effectively inhibited the self-discharge of AEESCs. The ultra-long self-discharge time is 37 160 s, and the capacitance retention rate is 95.1% after 8000 cycles.

Entirely photopatternable solid organic electrochemical transistors were fabricated and their excellent performance and pronounced hysteretic behavior studied in detail.

Prepared by weak epitaxy growth, fluorescent phenanthroimidazole derivative 2FPPICz molecules form crystalline thin films. The orientation is resolved, providing a structure foundation for crystalline thin-film organic light-emitting diodes.

New semiconducting D–A molecules with a fused tetrathiafulvalene–naphthalene diimide framework show near-infrared absorptions and emissions with maxima up to 1062 nm and quantum yields up to 1.64%.

A polymer, COP-Ta, was designed and synthesized. It served as a turn-on fluorescent sensor for hydrazine detection with high performance.

Utilizing the symmetry-breaking and π-bridge-extending strategy, three non-fullerene acceptors with DA′D core unit and electron-withdrawing unit are designed and synthesized via changing the alkoxy-substituted thiophene bridge unit.

All-small-molecule organic solar cells with high photovoltaic performance and low non-radiative energy losses ≤ 0.2 eV.

Room-temperature operated photodetectors without transparent conductive oxide electrodes by conjugated polymers mixed with conductive inorganic quantum dots, exhibiting the detectivities over 10¹² Jones from 300 nm to 2000 nm, were demonstrated.

To realize the direct and prompt detection of solid veterinary drug additives (VDAs), we prepared a highly sensitive solid sensor based on the synergism between hydrogen bonds and low-dimensional polymer networks to enable a detection limit below 1 ppm.

Two small donors with alkyl chains close to (Se-1) and away from (Se-2) the donor core were synthesized. Ordered molecular packing and an induced face-on packing by PJ1 enable an efficient charge generation and low V_oc loss in the Se-2/PJ1 device.

The absorbed water from air into cellulose/ionic liquid gel dramatically increases the apparent ionic Seebeck coefficient. The reason is the hydrovoltaic voltage that depends on the kinetics of water absorption/desorption at different temperature.

A resistive switching memory device based on a 2DP_TPAK+TAPB film with the conformational change mechanism was prepared and the memory behaviors can be adjusted by the degree of conformational changes.

Novel (trialkylsilyl)ethynyl-substituted DNTT derivatives are synthesized, and their crystal structures, transport properties, and the structure–property relationship are elucidated.

We developed a solid additive (uv-9) showing immiscibility with active layers for morphology control, a PCE of 17.18% was achieved, which is much higher than those of devices without any additives. Moreover, the generality of uv-9 has been verified.

The L4 molecular chirality can be amplified to a supramolecular scale by coassembling with SDS. Further incorporation of the CB[8] leads to a chirality inversion via a change from lamellar structure of L4/SDS to rectangular stacking in L4/SDS/CB[8].

A supramolecular phosphorescent switch, composed of a linear assembly formed by a photosensitive bromophenylpyridium derivative and cucurbit[8]uril, can respond to the dual stimulation of ultraviolet light and heating with good reversible stability.

The co-crystallization strategy has offered an efficient route to achieve high-performance n-type semiconductors through charge-transport switching from pristine p-type azaacene derivatives.

An asymmetric acceptor 5T-2C8-2Cl has been designed and an efficiency of 13.02% with simultaneously improved J_sc and V_oc has been achieved.

DPP-based conjugated polymers were synthesized via environmentally benign direct arylation polycondensation. With these polymers, OTFTs with μ_e values of up to 2.79 cm² V⁻¹ s⁻¹ were fabricated using a green solvent anisole.

Chromophore shielding is critical for twisted single core perylene bisimides used as non-fullerene acceptors in organic solar cells. Inherent chirality becomes only important for close packing chromophores as single crystal structure analyses reveal.

An n-type narrow-bandgap organoboron polymer with quinoidal character is synthesized by direct arylation polymerization. This polymer shows a narrow bandgap of 1.50 eV and could also be readily n-doped for thermoelectric applications.

An anionic radical through the charge transfer process of hybridization on the spinterface was found in a doped P3HT spin valve, which may effectively enhance the device performance.

Doping of graphene by self-assembled molecular network of uncharged dibenzyl viologen (DBV⁰) generated in situ.

Substituting electron-donating and electron-accepting substituents on antiaromatic pentalene cores can significantly tune the optical absorption, energy levels, antiaromaticity, and transistor switch-on behavior.

A series of highly conducting organic metal chalcogenides Cu_xBHT (x = 3, 4, and 5.5) were precisely constructed via variation of the molar ratio of Cu₂O and BHT, and a chemical transformation can be realized within the Cu_xBHT family by oxidation regulation.

A series of electron-deficient conjugated polymers (P(DTCDI-T), P(DTCDI-2T) and P(DTCDI-3T)) are reported as effective ETLs for inverted PSCs, resulting in a champion power conversion efficiency (PCE) of 17.88% for P(DTCDI-2T) ETL based devices.

A cationic water-soluble conjugated polymer with a D–A structure demonstrated high photothermal conversion efficiency and effective antibacterial ability under 808 nm irradiation.

1D conjugated coordination polymers M-DHBQ (M = Mn, Zn, and Ni) were constructed for sodium-ion batteries. Ni-DHBQ delivered the highest performance. These results highlighted the importance of metal ions for high performance batteries.

A novel self-assembled monolayer of o-carborane on gate oxide not only realized p-channel organic field effect transistors with low threshold voltage and high field effect mobility, but also enabled ambipolar charge transport in a typical n-type organic semiconductor.

The substituent effects in methyl- and methoxy-substituted thienothiophene–bis(oxoindolinylidene)benzodifurandione copolymers on field-effect performances were studied.

Photonic synaptic transistors based on space-confined-drop-casting-produced 2D crystals of conjugated polymers perform typical synaptic functions.