Themed collection 2015 Journal of Materials Chemistry C Hot Papers

In this Highlight, we summarize some recent advances in the area of red to near-infrared fluorescent AIE-active organic materials via tailoring the building block of quinoline-malononitrile (QM), and its application in bioimaging.

We highlight our recent efforts in developing devices that control the flow of H⁺ and OH⁻ in biological polymers.

Current issues/challenges in the development of biocompatible eumelanin-based devices ranging from commercial eumelanins through 5,6-dihydroxyindole polymers to mussel-inspired polydopamine are presented.

This highlight overviews state-of-the-art methods to pattern liquid metals for use in microfluidics and electronic components that are soft, stretchable, and shape reconfigurable.

A review on the recent developments of boron based shape and stimuli sensitive functional luminescent materials is presented.

Crystal organometal halide perovskites with specific morphologies and unique optoelectronic properties have extended their applications into the whole optoelectronic field.

In this review we aim to present an overview of the work that has been performed on attaching and studying Single-Molecule Magnets (SMMs) on various surfaces, with an emphasis on molecular design for surface interaction and on the magnetic properties before and after adhesion occurs.

Metal-free dyes with rigidified-aromatic segments as the conjugated spacers for dye-sensitized solar cells are compiled and reviewed.

Tunable photonic crystals (TPCs) represent an important class of intelligent materials, which can be used as optically active components and as functional technology to change an object's colour. Here, we review progresses in electrically responsive PCs: a subclass of these smart materials which employs electrical stimulation as direct or indirect trigger for tuning optical properties.

Ultrathin graphene, a 2D material, demonstrates outstanding features and rapid growth for EMI shielding due to its strong absorption towards electromagnetic waves in composites. It is sought after for communication, electronic devices, information security, electromagnetic pollution defense and healthcare.

This review charts the development of dip-pen nanolithography (DPN) for the fabrication of nanoscale bioelectronic and biomaterial interfaces.

The synthesis and applications of artificial porphyrinoids containing various functional building blocks by replacement of the pyrrole subunit have been summarized.

Soft lithographic methods describe a set of printing methods which are widely used for the preparation of structured surfaces.

Graphene quantum dots have large surface area, high photostability, excellent biocompatibility and versatile photoluminescence, promising for various applications.

Aggregation-induced emission and delayed fluorescence are observed simultaneously for the luminogens with an electron-donor and acceptor framework.

The formation of guest-mediated π-donor/acceptor stacks within electroactive metal–organic frameworks activates long-range charge mobilization, boosting the electrical conductivity of the doped materials.

This communication describes a novel strategy for the generation of gas-filled capsules embedded with functional species in the membranes on demand.

We demonstrate a solution-based method by a writing brush to realize the controllable fabrication of highly-oriented and large-scale TCNQ microwire arrays, which can be grown on rigid and flexible substrates.

A naphthyl anthracene derivative showed good carrier mobility and high luminescence, indicating the potential applications in multifunctional optoelectronics.

Two new 2D covalent organic frameworks were synthesized based on a triazatruxene unit, which could be used as potential fluorescent sensors for electron rich/deficient arene vapors.

Multi-scale thermal stability of (K,Na)NbO₃-based perovskites with a high d₃₃ of 430 pC N⁻¹ is investigated, revealing the origin of its large piezoelectricity.

Interpenetrating polymer networks composed of a crosslinked azobenzene liquid-crystalline polymer and poly(alkyl methacrylate)s were developed to enhance the photoresponsive and mechanical properties of photomobile polymer materials.

Femtosecond optical spectroscopy reveals coherent structural trapping accompanying spin-state photoswitching in a Fe^III spin-crossover material.

The composites composed of the cobalt terpyridine complex [Co^II(MeO-terpy)₂]₂₊ and the diblock copolypeptide amphiphiles (including glutamic acid and leucine) with rectangular morphology and reverse spin transition were prepared.

A novel Λ-shaped donor–π–acceptor–π–donor molecule BCPMM with AIEE, CIEE and polymorphism-dependent fluorescence properties was utilized to construct five simple logic gates and more than ten kinds of sequential combinational logic systems.

Lysine and dithiothreitol promoted ultrasensitive optical and colorimetric detection of mercury using anisotropic gold nanoparticles.

The skin morphology of cephalopods endows them with remarkable camouflage capabilities. Herein, we report infrared invisibility stickers inspired by the structures and proteins found in cephalopod skin. These stickers enable arbitrary objects to acquire reconfigurable infrared camouflage patterning. Our work represents an initial step towards wearable biomimetic infrared stealth technologies.

The naphthalenyl ethynyl substitution at the 1- and 2-positions of anthracene exhibits totally different film forming ability and hole mobility.

An ionic liquid–polymer (IL–PVP) dielectric layer with robust mechanical strength and flexibility was fabricated by a chemical interaction between the ionic liquid and polymer. This dielectric layer allowed operation of flexible thin film transistors with high performance.

A facile one-step procedure for solvothermal synthesis of highly water-dispersible biocompatible magnetic Fe3O4 nanoparticles mediated by cucurbit[n]urils (CB[n]s) was presented.

Porphyrin-based one-dimensional chains, ladders, and two-dimensional networks incorporating the p-block element Pb are assembled on a Au(111) surface.

A stimulus (vapour/heat)-responsive fluorescent dye as well as a luminescent conjugated polymer were readily generated using a reactive inkjet printing system.

The facile fabrication of various porphyrin nanostructures at an oil–aqueous interface is demonstrated. The obtained structures vary depending on assembly temperature, and include tree-, wavy-, honeycomb, ring-, skeleton-, jar-, hollow spherical and flask-like.

A new concept of phosphorescence switch and logic gate has been proposed based on iridium(III) complexes containing triarylboron moieties.

A novel bipolar phosphor BZQPG realizes a series of highly efficient orange-red PhOLEDs with the wide-range doping concentrations of 15, 20 and 25 wt%. They exhibit stable CIE_x,y (0.57 ± 0.01, 0.41 ± 0.01) and constantly high peak PE and EQE values of >60 lm W⁻¹ and 22%, respectively.

In this work, we report on the electrical characterization of nanoparticular thin films of zinc oxide and aluminum-doped ZnO. Temperature-dependent current–voltage measurements revealed that charge transport is well described by the Poole–Frenkel model.

Gold nanoribbons with high morphological yield and great SERS performance have been successfully prepared by using binary surfactants.

A room-temperature method based on phase transfer and reaction between Zn²⁺ and S²⁻ in toluene for coating a ZnS shell on quantum dots.

The assigned anomalous upconversion emission intensity of the ⁵D₀ → ⁷F₄ transition of Eu³⁺ in the double perovskite Sr₂Ca(W_1−xMo_x)O₆ co-doped with Yb³⁺ is shown to be due to a transition metal impurity present in the MoO₃ starting material.

Bio-inspired electrochromic V₂O₅–polymer hybrid films were prepared following a one-step self-organization procedure based on liquid crystal formation of organic and inorganic components.

A flexible heterostructure is reported herein, which elastically couples the volumetric variation during SCO to the electrical conductivity of a strain-sensitive metallic conductor, thereby resulting in synergistic electrical bistability.

Room temperature synthesis of micelle-protected highly fluorescent carbon nanodots (CNDs) and fabrication of scratch-resistant CND–ORMOSIL films and paint.

Silicon thin films that fulfil the needs of current semiconductor lithography were prepared from a new class of polycyclosilane–polysiloxane hybrid materials.

Effects of side groups on the kinetics of charge carrier recombination are investigated in dye molecule-doped multilayer organic light-emitting diodes by transient electroluminescence.

Ferroelectricity and piezoelectricity in CsBiNb₂O₇ are demonstrated for the first time.

In this study, high concentration or pure high boiling temperature solvent, chloronaphthalene (CN) was used as solvent for fabrications of efficient PSCs. The effects of high concentrations/purity of CN as solvent on device performances were reported.

We address the question of charge delocalization in amorphous and crystalline fullerene solids by performing state of the art calculations encompassing force-field molecular dynamics, microelectrostatic and quantum-chemical methods.

Oligothiophene-based liquid crystals having a wide luminescent color variation exhibit reversible luminescent color changes induced by mechanical shearing and subsequent aging at ambient temperature.

A dual responsive probe capable of generating two different responses upon reacting with thiols and H₂O₂ in a highly selective manner was developed.

SiQDs with an average diameter of 2.6 ± 0.5 nm are used as the light emitting material in high-efficiency inverted structure light emitting diodes.

RE₃Sb₃Zn₂O₁₄ (RE = La, Pr, Nd, Sm, Eu, Gd) is a series of novel pyrochlore-related materials with 2D Kagome lattices formed by RE³⁺ and Sb⁵⁺. The rare earth is the only magnetic ion in the structure; this family is therefore an archetype for exploring magnetic frustration on a 2D Kagome lattice.

A memory device was fabricated based on KCu₇S₄ nanobelts/Cu Schottky diode which displayed typical resistive switching behavior with a low set voltage of 0.4–1 V, a current ON/OFF ratio of ∼10⁴, and a retention time >10⁴ s.

Three push–pull aminopyridine derivatives having D–π–A, D–(π–A)₂, and D–(π–A)₃ arrangements were examined as model organic chromophores capable of intercalation into inorganic layered materials.

An organic–inorganic hybrid co-crystal complex exhibits an attractive switching nonlinear optical performance with a superior contrast and high repeatability.

We accurately measure the electrical properties of individual Fe₃₀Co₆₁Cu₉/Cu multilayered nanowires using nanomanipulators in in situ SEM to reveal that interfacial transition layers are influential in determining their transport behaviors.

Ge alloyed Cu–Te thin films showing improved thermal stability and enhanced retention properties when implemented as a cation supply layer in conductive bridge random access memory cells.

Green phosphorescent inverted organic light-emitting diodes (IOLEDs) with 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile (HAT-CN)/aluminium/n-doped 4,7-diphenyl-1,10-phenanthroline (Bphen) used as an electron injection layer (EIL) were demonstrated.

We demonstrate a novel two-dimensional material, fluorinated graphitic carbon nitride (g-C₃N₄) nanosheets, with intrinsic ferromagnetism; its Curie temperature can reach as high as 700 K.

We have demonstrated Cu_2−xAg_xCdSnSe₄ nanocrystals can result in decreases in the lattice thermal conductivity while increasing the Seebeck coefficient. A ZT up to 0.8 was obtained when x is 0.3.

The magnetocaloric effect of an inorganic framework material with repeating GdF₃ units has been studied using isothermal magnetization and heat capacity measurements.

We report a new strategy for the synthesis of Ag@Ag–Au core–frame nanocubes by co-titrating AgNO₃ and HAuCl₄ concomitantly into an aqueous suspension of Ag nanocubes in the presence of ascorbic acid (AA) and poly(vinyl pyrrolidone) at room temperature.

For stacked metamaterials, meta-atoms act as real atoms in nature materials, whose characteristic frequency bands behave as the equivalent energy levels.

We propose an in situ poling of vertically well-aligned piezoelectric nanowire arrays with preferential polarization orientation as highly sensitive self-powered sensors for monitoring vital signs.

The integration reliability of mechanically robust, ultra low-k spin-on-glass poly(methyl)silsesquioxanes incorporating incompletely condensed methyl-POSS were examined for next generation microelectronics.

Appropriately designed pyrrolidinofullerenes loaded with electron donor alkoxy groups showed enhanced V_OC and power conversion efficiencies in organic solar cells.

Introducing benzene derivative isolation groups into the π-bridge improved the EO coefficient (r₃₃) greatly.

A series of green-yellowish-orange-emitting Eu²⁺,Mn²⁺-doped Na₃LuSi₂O₇ (NLSO) phosphors, synthesized via the high-temperature solid state reaction process, have been investigated in detail.

A strategy for enhancing the sensitivity of optical thermometers is developed herein by using non-thermally coupled levels of Er³⁺.

Flexible and transparent BC/PU composites were prepared, which exhibit excellent transparency (up to 90%) in the visible region and great mechanical properties, with a tensile strength of up to 69 MPa and a Young's modulus of up to 6 GPa.

Fully efficient Nd-to-Er energy transfer has been studied at the molecular level in the heterobimetallic NdYb₂Q₉ light molecular converter.