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We report an instrument with the combination of solution jet beam deposition method and ultraviolet photoelectron spectroscopy (UPS). The solution jet beam method is a novel technique to fabricate organic thin films in vacuum, where solution of the organic material is sprayed in vacuum. This method can be applied to organic materials which cannot be vacuum evaporated due to thermal decomposition, e.g., ionic organic solids such as cyanine dyes. The present instrument combines this method with UPS, which is a powerful method for investigating the electronic structure of solids. Using this instrument, the UPS spectra of cyanine dye films deposited by the solution jet beam method were measured without exposure to air. The observed spectra were clearer than those of spin-coated films exposed to air. [ABSTRACT FROM AUTHOR]

Abstract: We report the solution jet beam method as a novel technique to fabricate organic thin films in vacuum. The method can be applied even to ionic organic materials, which cannot be vacuum evaporated due to thermal decomposition. Thin films of RhB (Rhodamine B) and Alq3 (tris(8-hydroxyquinoline)aluminum) were fabricated and characterized. Organic light emitting diodes (OLEDs) were also fabricated using Alq3 films prepared by this method. [Copyright &y& Elsevier]

Co 3d → 2p X-ray emission spectra of LaCoO[sub 3] in the Co 2p photoabsorption region are measured at 40 and 300 K. The spectra mainly reveal features nearly independent of excitation photon energy. This indicates the highly covalent or strongly hybridized nature of the Co 3d state. The emission component showing resonant behavior is also observed. The temperature dependence of the resonant emission confirms that the wave function of Co 3d electrons is totally symmetric in the low-spin ground state and that for the spin state excited thermally through the magnetic transition around 100 K is not. [ABSTRACT FROM AUTHOR]

Ce 4f electronic states in an antiferromagnetic Kondo compound CePd[sub 2]Si[sub 2] and a strong intermediatevalence compound CeNi[sub 2]Si[sub 2] have been investigated by means of high-resolution Ce 4d-4f resonant photoemission spectroscopy at 12 K. The relative intensity of the f[sub 5/2]¹ to f[sub 7/2]¹ final state in the Ce 4f spectrum for CeNi[sub 2]Si[sub 2] is stronger than the relative intensity for CePd[sub 2]Si[sub 2], indicating that the intensity of Kondo resonance scales the Kondo temperature since the Ce 4f spectrum near the Fermi level dominantly reflects the bulk component. Both Ce 4f spectra have been well fitted by the spectral calculations based on a single impurity Anderson model with consideration of the bulk and surface components. Our present calculation indicates that the model is applicable to the analyses of the Ce 4f spectra of the weakly and strongly hybridized systems. [ABSTRACT FROM AUTHOR]

Protective-layer-coated single-walled carbon nanotubes (SWNTs) with palladium nanoparticle decoration (Pd–SiO2–SWNTs) were fabricated and their sensing properties for hydrogen (H2) were investigated. SWNTs were coated with a 3–4 nm thick SiO2 layer by pulsed laser deposition and subsequently decorated with Pd nanoparticles by electron beam evaporation. Even though the SWNTs were completely surrounded by a protective layer, Pd–SiO2–SWNTs responded to H2 down to a concentration of 1 part per million. Compared with the Pd nanoparticle-decorated SWNTs without a protective layer (Pd–SWNTs), Pd–SiO2–SWNTs exhibited highly stable sensor responses with variations of less than 20%; Pd–SWNTs showed a variation of 80%. The density of the Pd–SWNTs significantly decreased after the sensing test, while that of the Pd–SiO2–SWNTs with the netlike structure remained unchanged. The hydrogen sensing mechanism of the Pd–SiO2–SWNTs was attributed to the chemical gating effect on the SWNTs due to dipole layer formation by hydrogen atoms trapped at the Pd–SiO2 interface. Moreover, the relationship between H2 concentration and sensor response can be described by the Langmuir isotherm for dissociative adsorption. [ABSTRACT FROM AUTHOR]