Publications by authors named "Hesham Fares"
Article Synopsis
- Plasmonic titanium nitride (TiN) is gaining traction as a substitute for noble metals in solar energy applications, enhancing photocatalytic and photovoltaic systems by generating hot electrons for improved efficiency.
- This paper introduces TiN nanoshells with a nonabsorbing dielectric core, which outperform conventional TiN nanospheres by providing better energy conversion, greater flexibility in design, and more effective hot electron production due to their smaller plasmonic shell size.
- The study evaluates the effect of different core materials (air, silica, and magnesium oxide) on the performance of nanoshells, calculating their absorption characteristics and identifying that hollow TiN nanoshells with the lowest core refractive index yield the highest efficiency in solar energy
There is currently a great deal of interest in realizing localized surface plasmon resonances (LSPRs) in two distinct windows in the near-infrared (NIR) spectrum for biosensing and medical applications, the biological window (BW) I and II (BW I, 700-900 nm; BW II, 1000-1700 nm). This study aims to demonstrate that LSPRs of Ga-doped ZnO (GZO) core-silver (Ag) shell structures exhibit promising features for biological applications in the NIR BW I and II. Here, we study three different shapes for nanoshells: the core-shell nanosphere, nanorod, and nanodisk.
View Article and Find Full Text PDFWe investigate the damping effects of coherent electron oscillations on the bandwidth of a quantized nanoparticle plasmon resonance. The nanoparticle (NP) is treated as a two-level quantum system, and the total relaxation time involves both the population relaxation time associated with radiative processes and the collisional relaxation time associated with nonradiative processes that result in dephasing/decoherence of electron oscillations. We describe the optical response of NPs to an external electromagnetic field by the optical Bloch equations employing the density matrix formalism to capture the quantum description nature of dipolar plasmon resonance and suggest a generalized criterion for the validity of dipole approximation.
View Article and Find Full Text PDFA quantum approach is developed for describing the behavior of Cherenkov radiation (CR). Then we propose a scheme of terahertz CR operating in a quantum regime for which the discreteness of momentum exchange in the free electrons-light interaction is significant. In this quantum regime, the spectrum of the emitted radiation appears as discrete spectral lines with a significantly narrow linewidth.
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