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Interest in layered two-dimensional (2D) materials has been escalating rapidly over the past few decades due to their promising optoelectronic and photonic properties emerging from their atomically thin 2D structural confinements. When these 2D materials are further confined in lateral dimensions toward zero-dimensional (0D) structures, 2D nanoparticles and quantum dots with new properties can be formed. Here, we report a nonequilibrium gas-phase synthesis method for the stoichiometric formation of gallium selenide (GaSe) nanoparticles ensembles that can potentially serve as quantum dots. We show that the laser ablation of a target in an argon background gas condenses the laser-generated plume, resulting in the formation of metastable nanoparticles in the gas phase. The deposition of these nanoparticles onto the substrate results in the formation of nanoparticle ensembles, which are then post-processed to crystallize or sinter the nanoparticles. The effects of background gas pressures, in addition to crystallization/sintering temperatures, are systematically studied. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy, and time-correlated single-photon counting (TCSPC) measurements are used to study the correlations between growth parameters, morphology, and optical properties of the fabricated 2D nanoparticle ensembles.
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This content will become publicly available on December 29, 2026
Large elastic anisotropy in Brillouin scattering of copper-intercalated GaS and GaSe
Brillouin scattering of bulk layered hexagonal gallium sulfide (GaS) and gallium selenide (GaSe) was measured both as pristine materials and intercalated with copper and silver. The sound velocities, refractive index, and four of the five independent elastic stiffnesses (cij) were determined. Values of the c11 elastic stiffness in thin crystals are higher than in previous measurements, bringing the elastic anisotropy (c11/c33) into a range typical of other layered materials. Copper intercalation showed a larger effect on acoustic phonons in GaS than in GaSe.
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- PAR ID:
- 10656328
- Publisher / Repository:
- AIP Publishing
- Date Published:
- Journal Name:
- Applied Physics Letters
- Volume:
- 127
- Issue:
- 26
- ISSN:
- 0003-6951
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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