Ultrafast photoluminescence dynamics of blue‐emitting silicon nanostructures

Abstract

What properties determine an effective nonlinear optical (NLO) material? These are reviewed and summarized for recently described borate compounds—materials that have proven to be superior to other commonly used NLO materials for UV applications. The Figure shows the arrangement of [B2O5] and [NbO6] groups within the unit cell of CsNbOB2O5.

Photoluminescence of silicon nanoparticles under the action of infrared femtosecond laser pulses

“…The measured spectra are similar in form to the photoluminescence spectra obtained at single photon excitation (when the energy of the exciting photon បω is larger than the bandgap E g ) and low intensities [29,30]. Perhaps this is due to the fact that the spectra were measured without temporal resolution and a high electron density in the conduction band existed for a very short time (about a few picoseconds).…”

“…However, in contrast to [29,30], when reaching a certain threshold inten sity, a clearly seen saturation is observed. …”

“…In recent years, femtosecond lasers have been applied to study the characteristics of photolumi nescence of various silicon nanostructures [28][29][30]. Using ultrafast laser sources makes it possible to carry out time resolved spectroscopy of the processes related to photoluminescence as well as to study the multiphoton excitation of silicon nanoparticles.…”