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This work serves as a roadmap for the development of a Vanadium dioxide (VO2)-Iridium composite based on the self-assembly of closely packed colloidal polystyrene microspheres (Pspheres) coupled with a Pulsed Laser Deposition (PLD) process. The self-assembly of a monolayer of PS is performed on an Al2O3 -c substrate, using an adapted Langmuir-Blodgett (LB) process. Then, on the substrate covered with P-spheres, a 50-nanometer Iridium layer is deposited by PLD. The Iridium deposition is followed by the removal of PS with acetone, revealing an array of triangular shaped metallic elements formed on the underlaying substrate. In a last deposition step, 50-, 100- and 200-nanometer thin films of VO2 are deposited by PLD on top of the substrates covered with the Iridium quasi-triangles, forming a composite. Adapting the size of the P-spheres leads to control of both the size of the Iridium micro-triangle and, consequently, the optical transmittance of the composite. Owing to their shape and size the Iridium micro-triangles exhibit localized surface plasmon resonance (LSPR) characterized by a selective absorption of light. Due to the temperature dependent properties of VO2, the LSPR properties of the composite can be changeable and tunable. [ABSTRACT FROM AUTHOR]

• TiC epitaxial films are grown by pulsed laser deposition (PLD). • (111) oriented TiC film grown on the MgO (111) and Al 2 O 3 (001) substrates. • Al 2 O 3 samples exhibit cyclic voltammograms significantly different from those on MgO. • A drastic composition change in carbon is anticipated for PLD-deposited TiC on Al 2 O 3. • Observed relaxation of the compressive interfacial strain confirms carbon deficiency. The electrochemical behaviour of titanium carbide (TiC x , with 0.5 < x < 1) thin films is presented and discussed with respect to their structural properties. Epitaxial (111)-orientated TiC films are grown onto (111)-cut MgO and (001)-cut Al 2 O 3 substrates by using TiC targets with various stoichiometry. When using a TiC target, the films grown on Al 2 O 3 substrates exhibit cyclic voltammograms significantly different from those grown on MgO. As a matter of fact, their electrochemical properties are strikingly similar to films with TiC 0.55 composition. It is demonstrated, by using high-resolution X-ray diffraction, that films grown on sapphire have a composition close to TiC 0.55 , the driving force for carbon deficiency being the relaxation of the compressive interfacial strain at the Al 2 O 3 /TiC interface. On the contrary, the interfacial strain at the MgO/TiC interface is tensile which cannot be compensated by variations in the Ti/C ratio. [ABSTRACT FROM AUTHOR]

Film growth of the well-known protein, chicken lysozyme, produced by the dry technique, pulsed laser deposition (PLD), from a compressed powder target has been investigated as a function of the target preparation pressure. PLD is a versatile technique for fabricating high quality films of inorganic materials, but the laser beam will typically produce fragments of molecules in the target and subsequently in the deposited films. We demonstrate that the pressure applied to compact the target prior to the laser irradiation is an important parameter that determines the deposition rate as well as the extent of fragmentation of the deposited molecules. The deposition process was carried out in vacuum using dry targets prepared with compaction pressure in the range 10–160 bar. The residual water in pockets of the lysozyme molecules drives fragments or intact lysozyme out of the target. At the intermediate fluence of 2 J/cm2, the deposition rate of the material (fragments or intact molecules) rises from 3 to 9 ng/cm2 per shot as the compaction pressure increases from 10 to 160 bar. However, the number of intact molecules falls down by almost two orders of magnitude in the same pressure range. This is explained by a stronger cohesion of the target material prepared at higher compression pressure, such that more energy and thus a higher temperature are required for the onset of material ejection. At the highest compression pressure, it means that no intact molecules survive the ejection. The results indicate that there is a pressure range where both a reasonable deposition rate and a considerable fraction of intact molecules in the films can be achieved. These experimental observations are consistent with the results of coarse-grained molecular dynamics simulations, where the fraction of intact lysozyme molecules is observed to vanish as the maximum temperature in the irradiated target increases. • The first systematic investigation of the dependence of the compression pressure of an organic target • High compression of a lysozyme powder target leads to the highest deposition rate. • Only at low compression of the lysozyme target the lysozyme molecules are transferred without fragmentation. • The lysozyme molecules seem to be fragmented at high pressure due to the high temperature needed for ejection. [ABSTRACT FROM AUTHOR]

Thermal behavior studies of several polymers, i.e. polyvinyl chloride (PVC), polyacrylic acid (PAA), and polyaniline (PAni), together with thin film deposition by a MAPLE technique, are presented. Thermal stability studies are important before attempting any laser-assisted processing of such materials, as this provides a better understanding of their molecular behavior, to assess the evolution and dynamics of the deposition. Thin films were grown on silicon substrates by means of matrix-assisted pulsed laser evaporation (MAPLE) using a Nd:YAG laser (266 and 355 nm, 7 ns pulse duration). Above the fluence of ~0.7 J/cm 2 the polymeric films are highly non-uniform due to the transferring of matrix-droplets and/or clusters from the target. At low fluence, typically between 0.1 and 0.5 J/cm 2 , the polymeric films are intact; the surface morphology is substantially improved and there are no measurable traces of the matrix molecules in the films. The important question of polymeric molecules integrity in the films with respect to that of the targets is discussed, in relation to their properties, and compared to data available in the literature. [ABSTRACT FROM AUTHOR]

Abstract: We present here results on samarium oxide thin films, obtained by pulsed laser deposition and by radio frequency assisted pulsed laser deposition. Three different substrate types were used: silicon, platinum covered silicon and titanium covered silicon. The influence of the deposition parameters (oxygen pressure and laser fluence) on the structure and morphology of the thin films was studied. The substrate-thin film interface zone was investigated; the optical and electrical properties (the losses, dielectric constant and leakage currents) were also determined. [Copyright &y& Elsevier]

The ability of matrix-assisted pulsedlaser evaporation (MAPLE)technique to transfer and deposit high-quality thin organic, bioorganic,and composite films with minimum chemical modification of the targetmaterial has been utilized in numerous applications. One of the outstandingproblems in MAPLE film deposition, however, is the presence of residualsolvent (matrix) codeposited with the polymer material and adverselyaffecting the quality of the deposited films. In this work, we investigatethe possibility of alleviating this problem by reducing the amountof matrix in the target. A series of coarse-grained molecular dynamicssimulations are performed for a model lysozyme–water system,where the water serves the role of volatile “matrix”that drives the ejection of the biomolecules. The simulations reveala remarkable ability of a small (5–10 wt %) amount of matrixto cause the ejection of intact bioorganic molecules. The resultsobtained for different laser fluences and water concentrations areused to establish a “processing map” of the regimesof molecular ejection in matrix-assisted pulsed laser deposition.The computational predictions are supported by the experimental observationof the ejection of intact lysozyme molecules from pressed lysozymetargets containing small amounts of residual water. The results ofthis study suggest a new approach for deposition of thin films ofbioorganic molecules with minimum chemical modification of the molecularstructure and minimum involvement of solvent into the deposition process. [ABSTRACT FROM AUTHOR]

Abstract: Thin films of [Cd{SSi(O–Bu t )3}(S2CNEt2)]2, precursor for semiconducting CdS layers, were deposited on silicon substrates by Matrix-Assisted Pulsed Laser Evaporation (MAPLE) technique. Structural analysis of the obtained films by Fourier transform infrared spectroscopy (FTIR) confirmed the viability of the procedure. After the deposition of the coordination complex, the layers are manufactured by appropriate thermal treatment of the system (thin film and substrate), according to the thermal analysis of the compound. Surface morphology of the thin films was investigated by atomic force microscopy (AFM) and spectroscopic-ellipsometry (SE) measurements. [Copyright &y& Elsevier]

We show that high-quality pentacene (P5) thin films of high crystallinity and low surface roughness can be produced by pulsed laser deposition (PLD) without inducing chemical degradation of the molecules. By using Raman spectroscopy and X-ray diffraction measurements, we also demonstrate that the deposition of P5 on Au layers result in highly disordered P5 thin films. While the P5 molecules arrange within the well-documented 1.54-nm thin-film phase on high-purity fused silica substrates, this ordering is indeed destroyed upon introducing an Au interlayer. This observation may be one explanation for the low electrical performances measured in P5-based organic thin film transistors (OTFTs) deposited by laser-induced forward transfer (LIFT). [ABSTRACT FROM AUTHOR]

Pulsed laser ablation of pure bismuth targets in a plasma discharge followed by thermal treatment as preparation method for humidity high-sensitive bismuth trioxide thin films deposited onto Si/Pt substrates were analyzed. Several thin films were deposited at different substrate temperatures during the pulsed laser deposition namely between 300 °C and 600 °C. Near to the electrical investigation, the structure and the morphology of the films as keys features for water adsorption are thoroughly investigated and correlated with their sensitivity as humidity sensors. Thus, it has been found that strong granularized Bi 2 O 3 thin films obtained through oxygen plasma-assisted pulsed laser deposition onto Si/Pt substrate at 500 °C provide the most interesting humidity sensing characteristics. [ABSTRACT FROM AUTHOR]