Rich stochastic dynamics of co-doped Er:Yb fluorescence upconversion nanoparticles in the presence of thermal, non-conservative, harmonic and optical forces

Abstract

The stochastic dynamics of individual co-doped Er:Yb upconversion nanoparticles (UCNP) were investigated from experiments and simulations. The UCNP were characterized by high-resolution scanning electron microscopy, dynamic light scattering, and zeta potential measurements. Single UCNP measurements were performed by fluorescence upconversion micro-spectroscopy and optical trapping. The mean-square displacement (MSD) from single UCNP exhibited a time-dependent diffusion coefficient which was compared with Brownian dynamics simulations of a viscoelastic model of harmonically bound spheres. Experimental time-dependent two-dimensional trajectories of individual UCNP revealed correlated two-dimensional nanoparticle motion. The measurements were compared with stochastic trajectories calculated in the presence of a non-conservative rotational force field. Overall, the complex interplay of UCNP adhesion, thermal fluctuations and optical forces led to a rich stochastic behavior of these nanoparticles.

Spectroscopic characterization of rare events in colloidal particle stochastic thermodynamics

“…Suggested improvements of this work include using a better model for the spectroscopic system, description of thermal effects, and considering the spatial averaging effect. The integrated stochastic-spectroscopic approach may also be Frontiers in Chemistry frontiersin.org extended to study other systems exhibiting nonlinear optical response, including dielectric micro-particles, plasmonic nanoparticles and nanorings (Nome et al, 2009;Nome et al, 2017b;Ferbonink et al, 2018).…”

Hydrogen peroxide disproportionation: time-resolved optical measurements of spectra, scattering and imaging combined with correlation analysis and simulations

“…We performed simulations with reflective boundary conditions to account for the finite sample volume (sample holder) and without (periodic boundary conditions). [13,24,25] Second, the macroscopic simulation system is then divided into mesoscopic cells that are much larger than the reactive Brownian particles yet much smaller than the system size. For each cell, we count particle numbers and then determine chemical species concentrations.…”

Femtosecond Laser Induced Luminescence in Hierarchically Structured Nd3+,Yb3+,Er3+ Co-Doped Upconversion Nanoparticles: Light-Matter Interaction Mechanisms from Experiments and Simulations

“…Moreover, ultrashort laser pulses have broad spectral bandwidth, broader than most of trivalent lanthanide doped-material absorption linewidth, and thus the spectroscopic study must be performed taking this regime into account, thereby adding further complexity to the light-matter interaction study. Nonetheless, considering the tremendous progress in fundamental understanding of the luminescent properties of lanthanide ions in complexes and host matrices [6][7][8][9] as well as UCNPs [10][11][12][13], together with the importance of UCNPs in basic science [14,15] and applications [16][17][18], understanding light-matter interactions involving femtosecond lasers and UCNPs may be useful in studies requiring higher energies, for example, in realtime applications and faster super-resolution bioimaging [19].…”

“…Nonetheless, considering the tremendous progress in fundamental understanding of the luminescent properties of lanthanide ions in complexes and host matrices [6][7][8][9] as well as UCNPs [10][11][12][13], together with the importance of UCNPs in basic science [14,15] and applications [16][17][18], understanding light-matter interactions involving femtosecond lasers and UCNPs may be useful in studies requiring higher energies, for example, in realtime applications and faster super-resolution bioimaging [19].…”