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Elucidating the Pulsed Laser Deposition Process of BiVO <sub/>4</sub> Photoelectrodes for Solar Water Splitting
摘要： BiVO4 thin films for the use as photoelectrodes for solar water splitting are prepared by pulsed laser deposition (PLD), a powerful technique to synthesize compact multinary metal oxides films with a high electronic quality. Here, the PLD process of BiVO4 films by ablating a BiVO4 target is systematically elucidated with a special focus on deviations from an ideal stoichiometric target-to-substrate material transfer. By correlating the V:Bi ratio of the films with their charge carrier transport properties and PEC performance, AM1.5 sulfite oxidation photocurrents of ~2.4 mA cm-2 at E = 1.23 V vs. RHE with stoichiometric films are achieved without any deliberate doping or surface modification. In addition, we prepare BiVO4 photoelectrodes for the first time by the alternating ablation of Bi2O3 and V2O5 targets. This approach is found to be an attractive alternative route to control the cation stoichiometry and produces BiVO4 films that generate AM1.5 sulfite oxidation photocurrents of up to 2.6?mA cm-2 at E = 1.23 V vs. RHE. Our results provide important insights into the PLD process of ternary oxide semiconductors and help to accelerate the synthesis and investigation of new multinary metal oxide photoelectrodes.
关键词： pulsed laser deposition,solar water splitting,stoichiometry,BiVO4,photoelectrodes
更新于2025-09-19 17:13:59
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Oxygen in Complex Oxide Thin Films Grown by Pulsed Laser Deposition: a Perspective
摘要： For thin film synthesis of complex oxides, one of the most important issues has always been how to oxidise the material. For a technique like pulsed laser deposition, a key benefit is the relatively high oxygen background pressure one can operate at, and therefor oxidation should be relatively straightforward. However, understanding the microscopic oxidation mechanisms turns out to be rather difficult. In this perspective, we give a brief overview of the sources of oxidation for complex oxide thin films grown by pulsed laser deposition. While it is clear what these sources are, their role in the kinetics of the formation of the crystal structure and oxygen stoichiometry is not fully understood.
关键词： High Tc superconductors,Oxidation,Thin films,Complex oxides,Pulsed laser deposition
更新于2025-09-19 17:13:59
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Structure Quality of LuFeO3 Epitaxial Layers Grown by Pulsed-Laser Deposition on Sapphire/Pt
摘要： Structural quality of LuFeO3 epitaxial layers grown by pulsed-laser deposition on sapphire substrates with and without platinum Pt interlayers has been investigated by in situ high-resolution X-ray diffraction (reciprocal-space mapping). The parameters of the structure such as size and misorientation of mosaic blocks have been determined as functions of the thickness of LuFeO3 during growth and for different thicknesses of platinum interlayers up to 40 nm. By means of fitting of the time-resolved X-ray reflectivity curves and by in situ X-ray diffraction measurement, we demonstrate that the LuFeO3 growth rate as well as the out-of-plane lattice parameter are almost independent from Pt interlayer thickness, while the in-plane LuFeO3 lattice parameter decreases. We reveal that, despite the different morphologies of the Pt interlayers with different thickness, LuFeO3 was growing as a continuous mosaic layer and the misorientation of the mosaic blocks decreases with increasing Pt thickness. The X-ray diffraction results combined with ex situ scanning electron microscopy and high-resolution transmission electron microscopy demonstrate that the Pt interlayer significantly improves the structure of LuFeO3 by reducing the misfit of the LuFeO3 lattice with respect to the material underneath.
关键词： in situ X-ray diffraction,multiferroics,electron microscopy,pulsed-laser deposition
更新于2025-09-19 17:13:59
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Influence of double pulse ablation on the film topography in picosecond pulsed laser deposition of nickel
摘要： An approach to achieve co-axial picosecond laser pulsed pair is proposed. Instead of introducing additional optical devices, this method involves the adjustment of switching-out dynamics in the regenerative amplification process. Experimental results concerning the dependence of laser output behavior on the duration of the quarter-wave voltage applied on the Pockels cell are reported. The influence of ablation mode (single pulse or double pulse) on the morphology of deposited Nickel-films is studied. A significant improvement in the surface morphology with the double pulse mode is observed. Fewer nanoparticles are observed and the thin film appears to be smoother with lower roughness.
关键词： double pulse ablation,nickel,film topography,picosecond pulsed laser deposition
更新于2025-09-19 17:13:59
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Love Wave Surface Acoustic Wave Sensor with Laser-Deposited Nanoporous Gold Sensitive Layer
摘要： Laser-deposited gold immobilization layers with different porosities were incorporated into Love Wave Surface Acoustic Wave sensors (LW-SAWs). Acetylcholinesterase (AChE) enzyme was immobilized onto three gold interfaces with different morphologies, and the sensor response to chloroform was measured. The response of the sensors to various chloroform concentrations indicates that their sensing properties (sensitivity, limit of detection) are considerably improved when the gold layers are porous, in comparison to a conventional dense gold layer. The results obtained can be used to improve properties of SAW-based biosensors by controlling the nanostructure of the gold immobilization layer, in combination with other enzymes and proteins, since the design of the present sensor is the same as that for a Love Wave biosensor.
关键词： pulsed laser deposition,Au,gas sensor,Love Wave,nanoporous film,SAW sensor
更新于2025-09-19 17:13:59
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Pulsed Laser Deposition Assisted van der Waals Epitaxial Large Area Quasi‐2D ZnO Single‐Crystal Plates on Fluorophlogopite Mica
摘要： There are still challenges in growth of transferable large area orientated ultrathin high-melting-point metal oxide single crystals with conventional methods. Herein, a new pathway to produce high quality single-crystal ZnO nanoplates with more than 400 μm crystal size is revealed by using the van der Waals epitaxy (vdWE) combined with pulsed laser deposition (PLD) method on fluorophlogopite mica. The quasi-2D ZnO plates as thin as 5 nm on fluorophlogopite mica without transition layer are achieved, showing an excellent thickness and orientation control while maintaining the excellent crystalline. ZnO nanoplates grown on conducting graphite and insulating hexagonal boron nitride (h-BN) 2D substrates are also obtained through PLD assisted vdWE. The transfer of 15 nm thick quasi-2D ZnO plates with 8 mm × 8 mm area onto a SiO2/Si substrate is successfully demonstrated. Based on the ZnO nanoplates, semitransparent self-powered ultraviolet (UV) photodetectors and light-emitting diodes centered at 400 nm UV region are demonstrated. This research highlights that the PLD assisted vdWE method is a fascinating way to fabricate high coverage ultrathin 2D ZnO plates with precisely thickness control for optoelectronic applications and may have enormous inspiration for other 2D nanomaterials growth.
关键词： pulsed laser deposition,van der Waals epitaxy,quasi-2D,ZnO single-crystal plate
更新于2025-09-19 17:13:59
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Direct growth of high-content 1T phase MoS2 film by pulsed laser deposition for hydrogen evolution reaction
摘要： The modified MoS2-based material, with a higher conductivity and rich active sites, is promising one of a variety of nonprecious-metal electrocatalysts for hydrogen evolution reaction (HER). Here, the bulk MoS2 is exfoliated to form small-size MoS2 clusters by pulse laser, which are diluted in solid sulfur and further to form porous film. The 1T phase MoS2 ratio in the prepared film was modulated by adding the different content of sulfur into MoS2 target. Besides, this addition also has an effect on the pore structure of films. Finally, the obtained high-content 1T phase MoS2 film provides the highly metallic conductivity and more active sites, which results in the more enhanced HER catalytic activity with a lower Tafel slope of 38 mV dec-1, a smaller overpotential of 151 mV at 10 mA cm-2, compared with the pure MoS2 film.
关键词： pulsed laser deposition,sulfur addition,1T phase MoS2,Hydrogen evolution reaction
更新于2025-09-19 17:13:59
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Improved ferroelectric response of pulsed laser deposited BiFeO <sub/>3</sub> -PbTiO <sub/>3</sub> thin films around morphotropic phase boundary with interfacial PbTiO <sub/>3</sub> buffer layer
摘要： (1 ? x)BiFeO3-xPbTiO3 (BF-xPT) is an interesting material for sensing and actuating devices with large polarization near the morphotropic phase boundary (MPB) (x = 0.30) in the bulk form. However, pulsed laser deposition (PLD) grown (BF-xPT) thin films usually show high electrical leakage and, hence, saturated ferroelectric hysteresis loops are only obtained at subzero temperatures. In this article, we report on high room temperature ferroelectric polarization with saturated hysteresis loops in pulsed laser deposited (BF-xPT) polycrystalline thin films of compositions near the MPB with the use of a thin buffer layer of PbTiO3 (PT). The thin films possessed a perovskite structure with excellent crystallinity and exhibit the presence of a monoclinic (Cm) phase (MA-type) for x = 0.20–0.25 and a mixture of a monoclinic (Cm) phase and a tetragonal (P4mm) phase for x = 0.30–0.35 compositions. The thin films with composition x = 0.25 exhibit a monoclinic phase and yield very large room temperature ferroelectric polarization (2Pr > 80μC/cm2), perhaps the highest room temperature ferroelectric polarization and excellent piezoelectric properties in PLD deposited (BF-xPT) thin films of near-MPB composition. Furthermore, the evolution of ferroelectricity with PT content, studied using room temperature Raman spectroscopy, reveals a correlation with lattice dynamics and stereochemical activity of Bi. Piezoforce domain analysis of the thin films reveals that ferroelectric polarization and electrical leakage in the thin films are intricately related to the type of domains present in the samples, viz., 180°, 109°, 90°, and 71° due to differences in the nature of the domain walls.
关键词： thin films,pulsed laser deposition,PbTiO3 buffer layer,ferroelectric response,BiFeO3-PbTiO3,morphotropic phase boundary
更新于2025-09-19 17:13:59
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In-Situ Plasma Monitoring during the Pulsed Laser Deposition of Ni60Ti40 Thin Films
摘要： The properties of pulsed laser deposited of Ni60Ti40 shape memory thin films generated in various deposition conditions were investigated. In-situ plasma monitoring was implemented by means of space- and time-resolved optical emission spectroscopy, and ICCD fast camera imaging. Structural and chemical analyses were performed on the thin films using SEM, AFM, EDS, and XRD equipment. The deposition parameters influence on the chemical composition of the thin films was investigated. The peeled layer presented on DSC a solid-state transformation in a different transformation domain compared to the target properties. A fractal model was used to describe the dynamics of laser produced plasma through various non-differentiable functionalities. Through hydrodynamic type regimes, space-time homographic transformations were correlated with the global dynamics of the ablation plasmas. Spatial simultaneity of homographic transformation through a special SL(2R) invariance implies the description of plasma dynamics through Riccati type equations, establishing correlations with the optical emission spectroscopy measurements.
关键词： thin films,in situ plasma monitoring,nitinol,pulsed laser deposition,fractal modelling,SL(2R) invariance,homographic transformations,Riccati equation
更新于2025-09-19 17:13:59
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Single-step growth of high quality CIGS/CdS heterojunctions using Pulsed Laser Deposition
摘要： This work reports on the utilization of pulsed laser deposition (PLD) for the preparation of CdS thin films and CdS/Cu(In,Ga)Se2 heterojunction structures on soda-lime glass (SLG) and Mo-coated SLG substrates, respectively, under various process conditions. Single phase, stoichiometric and high optical quality CdS films are obtained at a fluence of 1.1 J/cm2 and at deposition temperatures of 200 – 400oC. The results of this investigation were used to grow CdS on Cu(In,Ga)Se2/Mo/SLG. Both Cu(In,Ga)Se2 and CdS layers have been deposited sequentially using PLD without interrupting the influence of CdS deposition temperature on the properties of CdS/Cu(In,Ga)Se2 heterojunction has been extensively studied and is reported herein for the first time. Low series and high shunt resistances are obtained for the samples where CdS was grown at 200 and 300oC. The CdS/Cu(In,Ga)Se2 diode grown at CdS deposition temperature of 300oC exhibits the lowest ideality factor and leakage current, indicating the better quality of the diode. The results of this work demonstrate that high-quality CdS/Cu(In,Ga)Se2 diodes are obtained using pulsed laser deposition in a single-step growth process, eliminating the need for selenization of Cu(In,Ga)Se2 and the use of other growth techniques such as chemical bath deposition for CdS.
关键词： CdS deposition temperature,Electrical properties,Pulsed Laser Deposition,CdS,Optical properties,CdS/CIGS junction
更新于2025-09-16 10:30:52