•Two native β-CD CSPs with similar surface concentration were prepared at CD's C2 and C6 positions via click chemistry.•The surface CD orientation plays an essential role in CSP's enantio-differentiation ability.•Elution order of specific racemates can be reversed by tuning the surface CD orientation.•MD simulation provides a robust tool for investigation of the CD's discrimination mechanism under “real” mobile phase.A novel native cyclodextrin (CD) chiral stationary phase (CSP) with single triazole-bridge at CD C2 position (CSP1) was prepared by anchoring mono(2A-azido-2A-deoxy)-β-CD onto alkynyl silica via click chemistry. The effect of CD orientation on single layer CD-CSP's enantioseparation was comprehensively investigated using CSP1 (reversed orientation) and our previously reported CSP2 (C6 single triazole-bridge, normal orientation) as well as a commercial CD-CSP (Cyclobond I 2000, hybrid orientation) by separating several groups of analytes in chiral high performance liquid chromatography. It is found that the CD orientation on silica surface plays an important role in separating different racemates. CSP2 with normal CD orientation affords best separation for isoxazolines while CSP1 with reversed CD orientation better separates naringenin, hesperetin and Tröger's base. CSP2 and Cyclobond I 2000 show comparable separation ability for dansyl amino acids while poor separation was found on CSP1. Besides, molecular dynamics simulation was performed under “real” separation conditions using flavanone as model analyte to reveal the essential factors for CD's chiral discrimination behaviors.Download high-res image (275KB)Download full-size image

The self-doping CH3NH3PbBr3 crystals were fabricated by modulating the molar ratio of PbBr2 to CH3NH3Br from 0.2 to 1.5 to afford p- and n-type materials. The effect of modulating the inorganic to organic content on crystal framework, optical properties, energy level, conductivity, carrier mobility and concentration of CH3NH3PbBr3 crystals were studied by X-ray diffraction (XRD), photoluminescence (PL), photoelectron yield spectroscopy (PYS), Hall-effect measurement and X-ray photoelectric spectroscopy (XPS). It is found that different precursor ratio results in different surface and bulk element composition of the CH3NH3PbBr3 crystals, which influences the intrinsic defects hence the conductivity of perovskite crystals. Low precursor ratios (Pb-poor/Br-rich growth conditions) gave p-doped crystals and vice versa, which is governed by the dominant intrinsic defects of crystals. In addition, the O in the surface composition was much higher than that inside of the crystals, indicating that the crystal surfaces were doped with O to form extrinsic defects.

The preparation of two novel multifunctional cyclodextrin (CD) separation materials and their ultimate enantioseparation performances in high performance liquid chromatography are reported. A mild thiol–ene click reaction was used to anchor 1-allylimidazolium-per(p-methyl)phenylcarbamoylated-β-CD and 1-allylimidazolium-per(p-chloride)phenylcarbamoylated-β-CD onto thiol-modified porous silica giving structurally well-defined stable cationic multifunctional CD chiral stationary phases (CSP1 and CSP2 respectively). These covalently bonded CD phases have typical interaction modes such as H-bonding, π–π effect, electrostatic and dipole–dipole interactions as well as steric effects which result in superior chiral resolution for a variety of chiral compounds in different separation modes. In a reverse-phase mode, both CSPs exhibited excellent separation abilities for isoxazolines, flavonoids, β-blockers, and some other neutral and basic racemates. In a polar-organic mode, isoxazolines and flavonoids were well resolved. CSP1 with an electron-rich phenyl substitution on the CD rims gave a better resolution for isoxazolines whereas CSP2 with an electron-deficient phenyl substitution on the CD rims gave better resolution for flavonoids. Among isoxazolines, 4ClPh-OPr gained a high selectivity and resolution up to 18.6 and 38.7, respectively, which is an amazing result for CD enantioseparation materials.

•The first F12CuPc-based transistor is presented.•FxCuPc were tuned to function as single-component p-, ambipolar and n-type for OTFT.•F12CuPc OTFT device were revealed to show an ambipolar performance in air.In this paper, fluorinated copper phthalocyanines (FxCuPc, x = 4, 8, 12, 16) were synthesized and their energy levels were tuned to function as single-component p-, ambipolar and n-type semiconductors for single-component organic thin-film transistors (OTFTs). The influence of number of fluorine atoms on molecule geometries, frontier molecular orbitals, thin film morphology and microstructure as well as molecular aggregation patterns is systematically investigated by quantum calculation, X-ray diffraction (XRD) and atomic force microscopy (AFM). OTFTs were fabricated to evaluate the semiconducting and charge transport properties of FxCuPc. Perfluorinated copper phthalocyanines (F16CuPc) exhibited an electron mobility of 0.27 cm2 V−1 s−1. In particular, F12CuPc OTFT device were revealed to show an ambipolar performance with carrier mobilities of 0.005 cm2 V−1 s−1 for holes and 0.006 cm2 V−1 s−1 for electrons in air.The semiconducting property of fluorinated copper phthalocyanines (FxCuPc) has been tuned from p-to ambipolar and finally n-type for single-component OTFTs in air.

This work presents an investigation of the charging behavior of carbon black (CB) particles dispersed in a low-permittivity medium Isopar L. Highly charged and stably dispersed CB particles in Isopar L were prepared by employing a nonionic surfactant polyisobutylene–mono-succinimide (T151) with basic functionality to treat CB with acidic functionality (oxidized with concentrated nitric acid). As expected, CB particles were successfully negatively charged and presented a remarkably high electrophoretic mobility of −11.56 × 10−10 m2 V−1 s−1 and a zeta potential of −180.3 mV at the T151 concentration of 2.0 wt%, which are the highest values for CB in nonpolar media reported by far. The dispersion stability of CB particles, dominated by the particle charge, was dramatically improved with T151 concentrations increased in the range from 1.0 to 5.0 wt%. Prototype electrophoretic display device based on 2.0 wt% T151 treated CB particles exhibited highly improved performance compared to that of device using pristine CB particles. The high charge density and excellent dispersibility in apolar solvents of CB nanoparticles imply their potential applications in other electronic fields, such as electrically conductive inks for various printed electronics and conductive materials for various sensors.

Two TPB-based HTMs were synthesized and their energy levels were tuned to match with perovskite by introducing electron-donating groups asymmetrically. The TPBC based doping-free perovskite solar cell afforded an impressive PCE of 13.10% under AM 1.5G illumination, which is the first case of an effective device with TPB-based doping-free HTMs.

Novel small-molecule hole transporting materials (HTMs) with a linear π-conjugated structure have been synthesized. The perovskite solar cell based on 2TPA-2-DP as the HTM exhibits an encouraging power conversion efficiency of 9.1% under AM 1.5 G (100 mW cm−2) illumination, which is the first demonstration of an effective perovskite solar cell using a linear structured HTM.

•The cold crystallization behavior of TPB and TTB powder and their π–π aggregation in film were studied for the first time.•Both TPB and TTB could form smooth film and effective π–π interactions with edge-on orientations.•Annealing process is propitious to the formation of more ordered microstructure, resulting in improved carrier mobility.•The cold crystallization character of HTMs could be employed to predict their film structural order degree and charge carrier mobility.In this paper, the thermally induced crystallization behavior of N,N,N′,N′-tetraphenylbenzidine (TPB) and N,N,N′,N′-tetra-p-tolylbenzidine (TTB) and their microstructure changes as well as π–π aggregation mode as film state were comprehensively studied. The influence of heating rate, annealing temperature and time on the non-isothermal crystallization behavior of TPB and TTB powder was evaluated by Jeziorny method. Cold crystallization with the transition of metastable state was observed for both TPB and TTB. The thermally induced microstructure alteration and aggregation pattern of TPB and TTB films were investigated using XRD, SEM and AFM. The results revealed that both TPB and TTB could form smooth amorphous thin film and effective π–π interaction with identical edge-on orientations. TTB was prone to pack with both edge-on and face-on orientations especially after annealing, which accounts for its relatively low hole mobility. Besides, a more ordered film microstructure was formed after annealing at 70 °C for 24 h, which results in nearly four times increase of the hole mobility.Graphical abstract

Four novel blue luminescent hole transporting materials with N,N′-di(p-tolyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine as the core, containing triphenylamine units and olefinic linkers were synthesized and characterized by FT-IR, 1H NMR and HRMS. Their optical, electrochemical and thermal properties were investigated. Quantum-chemical calculations were performed to obtain their optimized structures and the electron distribution of the molecular orbital energy levels, and the experimental findings suggest that monosubstituted compounds have a similar energy gap to the bisubstituted compounds. The UV–Vis and photoluminescence spectra indicate that these compounds are blue luminescent materials. Cyclic voltammetry measurements show that the four compounds embody suitable highest occupied molecular orbital levels (in a range of −5.08 ∼ −5.14 eV) for hole injection. All of the compounds have excellent thermal stability, with decomposition temperatures above 400 °C and glass transition temperatures above 100 °C, which is of benefit to form stable amorphous glassy states.Graphical abstractHighlights► Four novel blue luminescent hole transporting materials containing triphenylamine units and olefinic linkers were synthesized and characterized. ► The synthesized compounds exhibit blue emissions, good solubility, the appropriate highest occupied molecular orbital energy level and high thermal stability. ► Quantum chemical calculations suggest that the energy gap can be effectively reduced by enlarge any part of conjugated structure. ► The new compounds offer potential for application in organic light-emitting devices.

Two new blue luminescent hole transporting materials (HTM) containing triphenylamine, carbazole units and olefinic linkers (TM1 and TM2) were synthesized via Wittig reaction and characterized by 1H NMR, FT-IR, and HRMS. The compounds show good solubility in common organic solvents such as dichloromethane, chloroform, tetrahydrofuran and dimethyl formamide. Their optical, electrochemical and crystalline properties were investigated by using UV–Vis, photoluminescence (PL) spectra, cyclic voltammetry (CV) and differential scanning calorimetry (DSC), respectively. Quantum-chemical calculation was performed to obtain their optimized structures and the electron distribution of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy levels. The UV–Vis absorption and PL spectra of the two compounds in solid state were found to be similar to that when they were in dilute THF, which suggests that these compounds remain as an amorphous state in solid films. CV measurements show that the two compounds embody suitable HOMO levels (in a range of −5.28 to −5.23 eV) for hole injection, which is consistent with the calculation consequence. Two compounds possess high glass-transition temperature (Tg) at 96.61 and 90.74 °C for TM1 and TM2, respectively, suggesting the two compounds could form stable amorphous glassy states. The experimental results show that the synthesized compounds have great potential for application in organic light-emitting devices (OLEDs).Graphical abstractHighlights► Two novel hole transporting materials were synthesized and characterized. ► Synthesized compounds exhibited good optoelectronic and thermal properties. ► Quantum chemical calculations have been utilized to support the experimental. ► Synthesized compounds have great potential for application in OLEDs.

•Complex nanostructure of CoPc and F16CoPc were grown via PVD.•The morphologies evolution process of nanostructures was clearly revealed.•The CoPc and F16CoPc ribbons exhibited excellent field-effect performance.•The hole and electron mobility for CoPc and F16CoPc-FET is 0.56 and 0.23 cm2 V−1 s−1 respectively.Complex micro-architectures of cobalt phthalocyanine (CoPc) and cobalt hexadecafluorophthalocyanine (F16CoPc) were grown via physical vapour deposition (PVD) method. For CoPc, the formation of “broom” architectures depends mainly on imposed pressure. While for F16CoPc, the emergence of intricate cluster or “flower” is mostly determined by furnace temperature. We show organic materials with π-conjugated structure could be purposefully sculpted into various morphologies through programmed modulations of environmental conditions. The morphological evolution of simple nanostructure to complex architecture was proposed. Further, the CoPc and F16CoPc crystals were applied to organic field-effect transistors (OFET) with hole and electron mobility of 0.56 and 0.23 cm2 V−1 s−1 respectively.Complex micro-architectures of CoPc and F16CoPc could be purposefully sculpted into various morphologies through programmed modulations of the growth conditions via physical vapour deposition method and showed excellent field-effect performance.

This work presents an investigation of the charging behavior of carbon black (CB) particles dispersed in a low-permittivity medium Isopar L. Highly charged and stably dispersed CB particles in Isopar L were prepared by employing a nonionic surfactant polyisobutylene–mono-succinimide (T151) with basic functionality to treat CB with acidic functionality (oxidized with concentrated nitric acid). As expected, CB particles were successfully negatively charged and presented a remarkably high electrophoretic mobility of −11.56 × 10−10 m2 V−1 s−1 and a zeta potential of −180.3 mV at the T151 concentration of 2.0 wt%, which are the highest values for CB in nonpolar media reported by far. The dispersion stability of CB particles, dominated by the particle charge, was dramatically improved with T151 concentrations increased in the range from 1.0 to 5.0 wt%. Prototype electrophoretic display device based on 2.0 wt% T151 treated CB particles exhibited highly improved performance compared to that of device using pristine CB particles. The high charge density and excellent dispersibility in apolar solvents of CB nanoparticles imply their potential applications in other electronic fields, such as electrically conductive inks for various printed electronics and conductive materials for various sensors.

Novel small-molecule hole transporting materials (HTMs) with a linear π-conjugated structure have been synthesized. The perovskite solar cell based on 2TPA-2-DP as the HTM exhibits an encouraging power conversion efficiency of 9.1% under AM 1.5 G (100 mW cm−2) illumination, which is the first demonstration of an effective perovskite solar cell using a linear structured HTM.

Two TPB-based HTMs were synthesized and their energy levels were tuned to match with perovskite by introducing electron-donating groups asymmetrically. The TPBC based doping-free perovskite solar cell afforded an impressive PCE of 13.10% under AM 1.5G illumination, which is the first case of an effective device with TPB-based doping-free HTMs.