An explanation was sought for unexpected fluorescence spectroscopy results
encountered when examining as-synthesized gallium selenide (GaSe) nanoparticles at
low temperatures, 20-240 K. Three types of spectroscopy were utilized in the process of
gathering data. UV-Vis absorption spectroscopy was employed at room temperature.
Static fluorescence spectroscopy was used in the temperature range from room
temperature down to 15-20 K and time-resolved fluorescence spectroscopy results were
gathered from 21 K to 240 K. The results are consistent with the idea that GaSe
nanoparticle nuclei exist in equilibrium with GaSe nanoparticles in the synthesis the
Kelley lab commonly uses. These nuclei are non-luminescent at room temperature due to
non-radiative losses, but emit strongly at low temperatures, approaching a quantum yield
of 1.0 at 21 K.