30 research outputs found
Synthesis of Black Phosphorene/P-Rich Transition Metal Phosphide NiP<sub>3</sub> Heterostructure and Its Effect on the Stabilization of Black Phosphorene
Black phosphorus (BP), as a direct band gap semiconductor material with a two-dimensional layered structure, has a good application potential in many aspects, but the surface state of it is extremely unstable, especially that of single-layer black phosphorus. In this study, BP crystals and two-dimensional black phosphorus (2D BP) are prepared by a mechanical ball-milling–liquid-phase exfoliation method. The X-ray diffraction (XRD) spectrum and high-resolution transmission electron microscopy (HRTEM) results showed that red phosphorus (RP) successfully turned to BP by the mechanical ball-milling method. The spectrophotometric analysis has detected absorption peaks at 780 nm, 915 nm, and 1016 nm, corresponding to single, double, and three-layer BP bandgap emission. A simple solvothermal strategy is designed to synthesize in-plane BP/P-rich transition metal phosphide (TMP) heterostructures (BP/NiP3) by defect/edge-selective growth of NiP3 on the BP nanosheets. HRTEM analysis indicates that the metal ions are preferentially deposited on the defects of 2D BP such as edges and unsaturated sites, forming a 2D BP/NiP3 in-plane heterojunction
Electron-deficient fullerenes in triple-channel photosystems
Fullerenes of increasing electron deficiency are designed, synthesized and evaluated in multicomponent surface architectures to ultimately build gradients in LUMO levels with nine components over 350 mV down to -4.22 eV
Solution-Processed and Air-Stable n‑Type Organic Thin-Film Transistors Based on Thiophene-Fused Dicyanoquinonediimine (DCNQI) Deriatives
π-Conjugated systems <b>2a</b> and <b>2b</b> containing
thiophene-fused DCNQI with long alkyl and trifluoromethylphenyl groups
were synthesized as potential active materials for solution-processed
and air-stable n-type organic thin-film transistors (OTFTs). The electrochemical
measurements revealed that the lowest unoccupied molecular orbital
(LUMO) of the compounds have an energy level less than −4.0
eV, indicating air stable n-type materials. The long alkyl groups
endowed the compounds good solubility and solution-processability.
X-ray diffraction measurements revealed the difference of the molecular
arrangement depending on the alkyl groups, which were also observed
in the UV–vis absorptions of the films. A relatively good mobility
up to 0.003 cm<sup>2</sup> V<sup>–1</sup> s<sup>–1</sup> for <b>2a</b> by spin-coating was obtained with good air stability