Abstract
Nonlinear emission properties of aggregated 50-nm gold nanoparticles (GNPs) excited by a femtosecond laser at 1560 nm are characterized. Aggregate forms are correlated to emission by scanning electron microscope imaging and pattern matching. Broad spectra in the visible region are obtained from aggregated GNPs, and their emission power exhibits a quadratic power dependence and an exponential decay in time due to morphology change. Polarization analysis reveals that longitudinal plasmonic modes play important roles for nonlinear emission. Relationships between brightness and morphology show that a large number of aggregates produce luminescence enhancement but with associated photo damage. It is proposed that characteristics of nonlinear emission from GNPs are explained by plasmon enhanced polarized hot electrons.
Original language | English (US) |
---|---|
Article number | 046007 |
Journal | Journal of Nanophotonics |
Volume | 11 |
Issue number | 4 |
DOIs | |
State | Published - Oct 1 2017 |
Keywords
- Nonlinear emission
- gold nanoparticle
- hot electron
- nanoparticle aggregation
- short-wave infrared
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics