Applied Physics
Yasamen H. Khadim; Uday M. Nayef; Falah A-H. Mutlak
Abstract
This study analyzes the effects of laser pulse energy set at 700 millijoules per pulse on silver, gold and silver@gold nanoparticles deposited on porous silicon (PS). Our main goal is to determine the optimal conditions by comprehensively evaluating their influence on structural, electrical, morphological ...
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This study analyzes the effects of laser pulse energy set at 700 millijoules per pulse on silver, gold and silver@gold nanoparticles deposited on porous silicon (PS). Our main goal is to determine the optimal conditions by comprehensively evaluating their influence on structural, electrical, morphological and optical properties. In pulsed laser ablation in liquid, a Nd:YAG laser with a pulse width of 10 nanoseconds and a wavelength of 1064 nm is used to produce the nanoparticles. X-ray diffraction (XRD) analysis confirms the crystalline growth of the core-shell nanoparticles with distinct peaks in the data confirming the presence of both Au and Ag nanoparticles. Morphological analysis shows a robust connection between the nanoparticles and the porous silicon layer, indicating structural stability. The UV–vis spectra show a localized surface plasmon resonance band (LSPR) in the range of 412–521 nm. It is noticeable that with increasing gold concentration the two peaks of the LSPR band converge to a single peak. Comparison of the photoluminescence emission spectra of the PS substrate and the NPs/PS shows a clear broadening of the emission band in PS, indicating a high-quality porous silicon structure. The intriguing properties of Ag@Au NPs make them promising for application in gas sensing systems.
Applied Physics
Eman M. Suliman; Uday M. Nayef; Falah A. Mutlak
Abstract
In this study, Au:TiO2 nanoparticles (NPs) are prepared by using the laser ablation method in liquid at different laser energies (600, 800, and1000 mJ). After that, Au: TiO2 NPs were deposited on porous-Si(PS). Porous silicon (PS) is synthesized by using the photo-electrochemical etching (PECE) of n-type ...
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In this study, Au:TiO2 nanoparticles (NPs) are prepared by using the laser ablation method in liquid at different laser energies (600, 800, and1000 mJ). After that, Au: TiO2 NPs were deposited on porous-Si(PS). Porous silicon (PS) is synthesized by using the photo-electrochemical etching (PECE) of n-type crystalline Si (c-Si) wafers of (100) orientation. The intensity of the etching current density was (4, 12, and 20 mA/cm2), with 16% (HF), and the etching time was 15 minutes. The X-ray diffraction (XRD) techniques, scanning electron microscopy (SEM), UV–visible spectrophotometry, and electrical properties are used to characterize the obtained particles. From the photo-detector measurements, the spectral responsivity curves three inclusive regions; the first peak was due to the absorption of UV light by Au: TiO2 NPs. The second peak was corresponding to the visible light absorption with the PS layer and the third peak was due to the absorption edge of the Si substrate. The higher responsivity of Au: TiO2 NPs/PS photo-detector was found to be 2.56A/W for specimens prepared at laser energy 800mJ.
