A charge carrier mobility of polymer films with the time-of-flight(TOF) technique using a fullerene layer was measured and the TOF photocurrent waveform can be remarkably improved.The 80-nm-thick fullerene layer is functioned as a charge-separation layer(CSL) which was placed between ITO electrode and the polymer layer of MEH-PPV(poly[2-methoxy-5-(2'-ethylhexyloxy) 1,4-phenylenevinylene]).In the CSL,the photo-generated holes and electrons can be efficiently separated,resulting in an enhanced current signal and great improvement of TOF waveform.The sample structure with fullerene layer exhibits a great advantage to measure the hole mobilities of polymers with low energy band gap.
320 years ago,the adhesive tendrils of Parthenocissus were studied.Recently,the permanent attachment system of the tendrils is retrieved concerns.Light microscopy,scanning electron microscopy and transmission electron microscopy observations provide sufficient information on the characteristic attachment structure.Histochemical,cytochemical and immunocytochemical methods unravel the sorts and the molecular compositions of the secreted adhesive fluid.This review provides a general overview of the whole research history and the latest progress in this field.The authors elaborate the adhesive tendrils of Parthenocissus from macroscopic morphology,through microscopic structure,secreted adhesive fluid,adhesive force and adhesion mechanism to bionic exploration and application.
As a component of near-field scanning optical microscope (NSOM),optical fiber probe is an important factor influncing the equipment resolution.Electroless nickel plating is introduced to metallize the optical fiber probe.The optical fibers are etched by 40% HF with Turner etching method.Through pretreatment,the optical fiber probe is coated with Ni-P film by electroless plating in a constant temperature water tank.Atomic absorption spectrometry (AAS),scanning electron microscopy (SEM),and energy dispersive X-ray spectrometry (EDXS) are carried out to characterize the deposition on fiber probe.We have reproducibly fabricated two kinds of fiber probes with a Ni-P film:aperture probe and apertureless probe.In addition,reductive particle transportation on the surface of fiber probe is proposed to explain the cause of these probes.
A series of alcohol soluble amino-functionalized carbazole-based copolymers were synthesized via Suzuki coupling reaction.The pendent amino groups endow them high solubility in polar solvents,as well as efficient electron injection capability from high work-function metals.The relationships between the photophysical and electrochemical properties and the polymer backbone structure were systematically investigated.These alcohol-soluble carbazole-based copolymers were used as cathode interlayers between the high work-function metal Al cathode and P-PPV emissive layer in polymer light-emitting diodes with device structure of ITO/PEDOT:PSS/P-PPV/interlayer/Al.The resulting devices exhibited improved performance due to the better electron injection/transporting ability of the designed copolymers from Al cathode to the light-emitting layer.
