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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]

The use of laser-based processing is presented here for the transfer of azo-derivatives, for optoelectronics assembly applications. Laser-printing techniques are also adequate tools for rapid prototyping of diverse materials, since they avoid the usage of solutions, moulds, lithography masks, etc. Here, we present a study on the laser-induced forward transfer (LIFT) and printing of micrometric-sized pixels (350 μm × 350 μm), by using matrix-assisted pulsed laser evaporation (MAPLE) deposited thin film donors. Due to their particular optical properties, i.e. second harmonic generation, optical limiting and all-optical poling, and with applications in optoelectronics and sensor development, azo-dyes have been intensively studied in bulk or as thin films. The influence of a metallic dynamic release layer (DRL) during LIFT is investigated. [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]

Highlights: [•] Ferrocenecarboxaldehyde thin films are grown on silicon substrates, by MAPLE. [•] Thin films with low roughness and preserved chemical structure are obtained. [•] Second harmonic generation capabilities of films are evidenced. [Copyright &y& Elsevier]

Abstract: Ferrocene – Fe(C5H5)2, the prototypical metallocene, is a type of organometallic chemical compound consisting of two cyclopentadienyl rings bound on opposite sides of a central iron atom. We discuss here on the growth of high quality, nanometric-sized ferrocene thin films by a non-conventional technique, i.e. matrix-assisted pulsed laser evaporation (MAPLE), on silicon and ITO coated glass substrates, by using a Nd:YAG pulsed laser device emitting at 266 nm (4ω). Spectroscopic-ellipsometry, Fourier transform infrared spectroscopy, scanning electron microscopy and atomic force microscopy techniques were used to investigate the structure, morphology and optical properties of the films. Low-to-medium second harmonic generation capabilities of the films were evidenced, when irradiated by a femtosecond Ti:sapphire pulsed laser. [Copyright &y& Elsevier]

Abstract: Lactoferrin (Lf) is an iron-binding glycoprotein present in almost all mammalian secretions which plays an important role in host defense against microbial and viral infections. The protein has been reported to also have anti-inflammatory activity and antitumoral effects in vitro and in vivo. Thin films of Lf were deposited on silicon, quartz and Thermanox plastic coverslip substrates by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique, using a Nd:YAG laser working at 266nm, at different laser fluences (0.1–0.8Jcm−2). The deposited layers have been characterized by Fourier Transformed Infra-Red spectroscopy (FTIR), and the morphology of the various substrates was investigated by Atomic Force Microscopy (AFM). The biocompatibility of lactoferrin thin films was evaluated for each substrate, by in vitro biochemical tests. [Copyright &y& Elsevier]

Abstract: Thin films based on two different metal–organic systems are developed by MAPLE and their nonlinear optical applications are explored. A complex of o,o′-dihydroxy azobenzene with Cu2+ cation is found to organize as a non-central symmetric crystallite. A simple protocol is developed for the in situ fabrication of highly monodisperse copper-complex nanoparticles in a polymer film matrix of polyacrylic acid. The thin films were deposited on quartz substrates by MAPLE (matrix assisted pulsed laser evaporation) using a Nd:YAG laser working at 355nm. Atomic force microscopy (AFM), Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and optical second harmonic generation (SHG) were performed on the samples. The optical limiting capability of the nanoparticle-embedded polymer film is investigated. [Copyright &y& Elsevier]

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]