Search results for "Nanosecond laser"

showing 2 items of 2 documents

Ethane-Bridged Zinc-Porphyrin Dimers in Langmuir-Shäfer Thin Films: Structural and Spectroscopic Properties

2006

This work reports on the structural and spectroscopic properties of ethane-bridged Zn porphyrin dimers (1) in Langmuir-Scha¨fer (LS) thin films by combining scanning force microscopy (SFM) with film balance, UV-vis absorption, fluorescence, and nanosecond laser flash photolysis measurements. Results show that depending on the surface pressure the Langmuir films of pure 1 can be arranged in two different condensed phases, whereas SFM of the LS films shows characteristic fractal networks constituted by nanoscopic aggregates. The spectral findings agree with a picture in which 1 is apparently present in the anti conformation but aggregated in a sort of H-type structure whose optical features r…

LangmuirPorphyrinsLangmuir-Schaefer filmPhotochemistryporphyrin dimerPorphyrinSurfaces Coatings and Filmscircular dichroismchemistry.chemical_compoundCrystallographychemistryUltrafast laser spectroscopyMaterials ChemistryArachidic acidFlash photolysisPhysical and Theoretical ChemistryAbsorption (chemistry)Thin filmChiralityUV-vis absorptionConformational isomerismfluorescence and nanosecond laser flash photolysis measurements
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Formation and Evolution of Nanoscale Metal Structures on ITO Surface by Nanosecond Laser Irradiations of Thin Au and Ag Films

2012

The effect of nanosecond laser irradiations on 5 nm thick sputter-deposited Au and Ag films on Indium-Tin-Oxide surface is investigated by atomic force microscopy (AFM) and scanning electron microscopy (SEM). After 500, 750, and 1000 mJ/cm 2 fluence irradiations, the breakup of the Au and Ag films into nanoscale islands is observed as a consequence of fast melting and solidification processes. The mean nanoparticles size and surface density are quantified, as a function of the laser fluence, by the AFM and SEM analyses. In particular, the comparison between the Au and Ag islands reveals the formation of larger islands in the case of Ag for each fixed fluence. The mechanism of the nanoscale …

NanoclusterMaterials scienceNanosecond laser irradiationScanning electron microscopeITO; Laser; Au; AgLaserNanoparticleNanotechnologyAgSettore ING-INF/01 - ElettronicaMolecular physicsFluenceSettore FIS/03 - Fisica Della MateriaMetalAtomic force microscopyAuGeneral Materials ScienceDewettingNanostructuringNanoscopic scaleBreakupvisual_artvisual_art.visual_art_mediumGoldNanosecond laserITO
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