How Glow-in-the-dark works
• All glow-in-the-dark products contain phosphors
• A phosphor is a substance that radiates visible light after
• Phosphors have three
• The type of energy they require
to be energized
• The color of the visible light that
• The length of time that they glow
Glow in the dark spectra
after being energized
• Glow-in-the-dark objects are
• Steps involved in phosphorescence
• Electrons are excited
• Excited electrons drop to a
lower, but still excited
intermediate level (Most light
• Electrons drop to ground state Blue, Green and Red Phosphors
• Steps to make a pickle glow.
–Large current flows through the pickle
–Pickle quickly heats up near the electrodes due to current
–At the electrodes water vaporizes.
–The region near one end goes dry first, so the large current
stops and all the voltage drops across this dry region.
–In this dry region impact ionization now takes place.
• e collides with Na, ionizing it etc.: e + Na → e + Na+ + e ...
• Na+ relaxes emitting a photon: Na+ + e → Na* → Na + n
–Just like in a Na vapor lamp!
Glowing Pickle Specta
Lithium Chloride Pickle 14000 pickle
• We used a re-pickled pickle.
Li Na pickle
Intensity (C/S ort au)
• The pickle was 10000 pickle pickle
“reconstituted” by soaking it
(C/S ort au)
in lithium chloride. 6000
• This caused 10000 to be some
red light in the spectrum 2000
along with the yellow light
400 500 600 700 800 900
from the sodium. Wavelength (nm)
Lithium Pickle peaks at 610nm, 670nm & 813nm
6000 Sodium pickle peaks at 589nm, 767nm & 770nm