Gallium phosphide (GaP) nanoparticulate thin films were easily fabricated by colloidal suspension deposition via GaP nanoparticles dispersed in N,N-dimethylformamide. The microstructure of the film was performed by x-ray diffraction, high resolution transmission electron microscopy and field emission scanning electron microscopy. The film was further investigated by spectroscopic ellipsometry. After the model GaP+void|SiO2 was built and an effective medium approximation was adopted, the values of the refractive index n and the extinction coefficient k were calculated for the energy range of 0.75 eV-4.0 eV using the dispersion formula in DeltaPsi2 software. The absorption coefficient of the film was calculated from its k and its energy gaps were further estimated according to the Tauc equation, which were further verified by its fluorescence spectrum measurement. The structure and optical absorption properties of the nanoparticulate films are promising for their potential applications in hybrid solar cells. 相似文献
Currently, one of the challenges in high‐resolution transmission electron microscopy (TEM) studies of nanomaterials is to make contamination‐free materials in a simple and time‐efficient way. Here, a method is demonstrated that combines nanosecond‐pulsed laser dewetting of thin films with a film float‐off technique to realize nanostructures (NSs) on electron‐transparent substrates in a robust and rapid manner. NSs of metal (Ag) and bimetals (AgCo, AuCo) ranging from 20 to 150 nm are synthesized on thin carbon film deposited on mica substrates. The NS/carbon system is subsequently transferred onto TEM grids by a float‐off process resulting from debonding of the carbon from mica due to their contrasting hydrophobic nature. This process enables the fabrication of different NSs on flexible and electron‐transparent substrates. 相似文献
Fourteen thin-film optical sensors in which halide-sensitive fluorophores are immobilized in a thin copolymer film (50 m, dry) have been developed and characterized. The sensor films use rhodamine, 6-methoxyquinoline, and harmane dyes which have been functionalized and bound to a hydrophilic copolymer. The sensor films are reversibly capable of determining aqueous bromide and iodide with 4 and 2% accuracy, respectively, at concentrations of around 10–3 mol dm–3, and are more sensitive than previous plastic sensor fabrications. The 90% response time to molar iodide is 30–60 s. A combination of sensor films allows the simultaneous determination of both I– and Br– in a mixed-halide solution. The interference of several ions, including pseudo-halides, on the sensor films has been studied. 相似文献