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Tunable thermo-piezo-plasmonic effect on core/shell nanoparticles under laser irradiation and external electric field
摘要： This work is focused on the characterization of the opto-heating generation in thermo-piezo-plasmonic solutions of gold-PbZrTiO3 (PZT) core/shell nanoparticles. Core/shell nanoparticles have been prepared by the laser ablation in liquid method. Linear and nonlinear optical properties of proposed nanoparticles were studied by optical spectroscopy and the Z-scan technique under external voltage to investigate the piezo-photonic effect. Furthermore, the linear optical properties of these nanostructures were calculated vie dipole approximation method with different core size and different shell thickness of samples immersed in water and poly-vinyl-pyrrolidone. In addition, thermo-plasmonic effects of samples are investigated theoretically and experimentally by the finite element method of COMSOL multiphysics V5.4 and infrared camera under laser irradiation and external electric field. The results revealed a clear tunable and adjustable linear and nonlinear behavior and thermo-piezo-plasmonic properties under external effects. The temperature elevation is ranging of ?T = 3.7–14.1 °C under different external effects. Accordingly, these results encourage to uses proposed samples for the cancer treatment and the different biomedical applications.
关键词： Nonlinear refractive index,External electric field,Core/shell NPs,Laser irradiation,Thermoplasmonic,Piezoelectric,Z-scan technique,Schottky barrier
更新于2025-09-23 15:21:01
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Insights into Ultrashort Laser-Driven Au:TiO <sub/>2</sub> Nanocomposite Formation
摘要： Modern methods of laser-based nanocomposite fabrication and treatment rely on a deep understanding of the interplay between a set of mechanisms involved, such as nanoparticle growth and decay, material phase transformation, degradation and damage. In this work, scanning multi-pulse femtosecond laser irradiation is used for Au : T iO2 nanocomposite formation. Depending on laser scan speed two di?erent regimes are observed revealing di?erent gold nanoparticle growth rates. The regime of the remarkably fast laser-induced growth of Au nanoparticles is found to be accompanied by the cavity formation in titania ?lm around the particles. The transition between two formation regimes is found to be abrupt con?rming the catastrophic mechanism of Au nanoparticle growth. The obtained results are analyzed based on the developed numerical model including e?ects such as nanoparticle absorption, local ?eld enhancement, photo-induced free carrier generation, plasmon-assisted electron emission, and thermal heat transfer from nanoparticles towards titania matrix. Our modeling reveals the crucial role of collective thermoplasmonic e?ects caused namely by bimodal nanoparticle size distribution. The performed analysis also suggests that spall in solid state is responsible for ?nal matrix degradation if nanoparticles become large enough. The considered laser-based formation of optical nanocomposites is crucial not only for the better understanding of ultra-short laser interactions with glass-metallic nanocomposite materials, but also for numerous applications in photocatalysts, solar cells, and chemo-sensors.
关键词： femtosecond laser,nanocomposite,thermoplasmonic effects,nanoparticle growth,Au:TiO2
更新于2025-09-23 15:19:57
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CW lasera??initiated formation of nanoa??Si crystals in glassa??metal nanostructures
摘要： Local and controllable growth of nanocrystalline silicon (nano-Si) in a commercial borosilicate glass is demonstrated. The nano-Si was formed in the subsurface region of the glass via aluminothermic reaction in the course of the irradiation of a 2D array of aluminum nanodisks fabricated on the glass surface with CW low-power 633 and 532 nm lasers. The thermoplasmonic nature of the nanodisks heating is demonstrated: at low incident intensity, the phenomenon takes place only if the plasmon resonance of the array and the laser wavelength are close enough. However, when the laser beam intensity at the sample surface exceeds 8 MW/cm2 mutual position of the plasmon resonance and the laser wavelength weakly influences the phenomenon. The nano-Si formation is studied with Raman scattering technique, and the average size of the silicon nanocrystals is evaluated.
关键词： nanocrystalline silicon,thermoplasmonic heating,aluminothermic reaction,laser irradiation,Raman scattering
更新于2025-09-19 17:13:59
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Ultrafast Modulation of Thermoplasmonic Nano-Bubbles in Water.
摘要： Thermo-optically generated bubbles in water provide a powerful means for active matter control in microfluidic environments. These bubbles are often formed via continuous-wave illumination of an absorbing medium resulting in bubble nucleation via vaporization of water and subsequent bubble growth from the inward diffusion of gas molecules. However, to date such bubbles tend to be several microns in diameter, resulting in slow dissipation. This limits the dynamic rate, spatial precision and throughput of operation in any application. Here we show that isolated plasmonic structures can be utilized as highly localized heating elements to generate thermoplasmonic nanobubbles that can be modulated at frequencies up to several kilohertz in water, orders of magnitude faster than previously demonstrated for microbubbles. The nanobubbles are envisioned as advantageous localized active manipulation elements for high throughput microfluidic applications.
关键词： thermoplasmonic bubbles,nanobubbles,thermoplasmonic phase change,bubble nucleation,thermoplasmonics
更新于2025-09-11 14:15:04