arXiv subjects

Gleb I. Tselikov

Publications and source records attributed to Gleb I. Tselikov.

3 recordsLinked to original sources

arXiv2025

Solvent-Directed Femtosecond Laser Ablation: Tuning Phase and Defect Engineering in Hybrid CdPS3/CdS Nanostructures

The limited visible-light absorption of wide-bandgap van der Waals crystals fundamentally restricts their utility in solar energy conversion. Here, we report a surfactant-free, solvent-directed laser synthesis strategy to engineer the phase and optoelectronic properties of Cadmium Phosphorus Trisulfide (CdPS3). By exploiting the non-equilibrium thermodynamics of femtosecond pulsed laser ablation in liquid (fs-PLAL), we demonstrate a tunable transition from the stoichiometric ternary phase to a highly active binary-rich heterostructure. While ablation in water preserves the monoclinic CdPS3 lattice, the reducing environment of isopropanol triggers the formation of CdS quantum dots and metallic cadmium defect sites. This solvent-induced phase engineering transforms the ultraviolet-active host into a robust visible-light photocatalyst. The resulting hybrid CdPS3/CdS nanocolloids exhibit superior charge separation efficiency, driven by Schottky-like metal-semiconductor junctions, achieving ~ 90% degradation of Methylene Blue under 532 nm irradiation within 30 minutes. This work establishes fs-PLAL as a scalable defect-engineering tool for complex ternary layered materials, offering a new design of high-performance metal-thiophosphate-based photocatalysts.

physics.app-ph↗

arXiv2025

Laser-Synthesized Amorphous PdSe$_{\mathrm{2-x}}$ Nanoparticles: A Defect-Rich Platform for High-Efficiency SERS, Photocatalysis, and Photothermal Conversion

The control of material properties at the atomic scale remains a central challenge in materials science. Transition metal dichalcogenides (TMDCs) offer remarkable electronic and optical properties, but their functionality is largely dictated by their stable crystalline phases. Here we demonstrate a single-step, ligand-free strategy using femtosecond laser ablation in liquid to transform crystalline, stoichiometric palladium diselenide (PdSe$_{\mathrm{2}}$) into highly stable, amorphous, and non-stoichiometric nanoparticles (PdSe$_{\mathrm{2-x}}$, with x$\approx$1). This laser-driven amorphization creates a high density of selenium vacancies and coordinatively unsaturated sites, which unlock a range of emergent functions absent in the crystalline precursor, including plasmon-free surface-enhanced Raman scattering with an enhancement factor exceeding 10$^\mathrm{6}$, a 50-fold increase in photocatalytic activity, and near-infrared photothermal conversion efficiency reaching 83$\%$. Our findings establish laser-induced amorphization as a powerful top-down approach for defect-engineered TMDCs and advances their practical usage in optics, catalysis, and nanomedicine.

cond-mat.mtrl-sci↗

arXiv2021

Nonlinear exciton-Mie coupling in transition metal dichalcogenides nanoresonators

Molybdenum disulfide (MoS2) is a layered material of transition metal dichalcogenides (TMDCs) with a high refractive index in the visible and infrared spectral range. Therefore, by constructing MoS2 into dielectric nanoresonators, one can generate highly confined electromagnetic Mie-type modes. In this work, we applied lithography and etching techniques to single crystal MoS2 flakes to fabricate nanodisks that support magnetic dipole Mie resonances in near infrared spectral range. The nanodisks were studied by second-harmonic generation (SHG) rotational anisotropy revealing the retention of crystallinity and the orientation of the crystallographic axes of the single disk structure after fabrication. Magnetic dipole resonances manifest as resonant intensity enhancement in SHG spectra. Tuning Mie resonances by selecting the geometrical size of MoS2 nanodisks, we demonstrated strongly enhanced SHG due to the overlap of the optical resonance at the fundamental wavelength with the C-exciton resonance at the second-harmonic wavelength.

physics.optics↗