Search results
Results from the WOW.Com Content Network
Unlike fluorescence, a phosphorescent material does not immediately reemit the radiation it absorbs. Instead, a phosphorescent material absorbs some of the radiation energy and reemits it for a much longer time after the radiation source is removed.
Phosphors can be classified into two categories: fluorescent substances which emit the energy immediately and stop glowing when the exciting radiation is turned off, and phosphorescent substances which emit the energy after a delay, so they keep glowing after the radiation is turned off, decaying in brightness over a period of milliseconds to days.
Persistent luminescence involves energy traps (such as electron or hole traps) in a material, [4] which are filled during the excitation. Afterward, the stored energy is gradually released to light emitter centers, usually by a fluorescence-like mechanism.
As the definition does not fully describe the phenomenon, quantum mechanics is employed where it is defined as there is no change in spin multiplicity from the state of excitation to emission of light. [2] Phosphorescence, traditionally defined as persistent emission of light after the end of excitation. As the definition does not fully ...
However, phosphorescent OLEDs generate light from both triplet and singlet excitons, allowing the internal quantum efficiency of such devices to reach nearly 100%. [5] This is commonly achieved by doping a host molecule with an organometallic complex.
Photostimulated luminescence (PSL) is the release of stored energy within a phosphor by stimulation with visible light, to produce a luminescent signal. X-rays may induce such an energy storage. A plate based on this mechanism is called a photostimulable phosphor (PSP) plate (or imaging plate ) and is one type of X-ray detector used in ...
That said, Vanessa Rissetto, R.D., co-founder of the virtual nutrition care service Culina Health, believes the FDA's move is a positive step forward."Early-stage cancers are on the rise across ...
Pearl Scene using phosphorescent paint, Irving Berlin's 1921 Music Box Revue. Phosphorescent paint is commonly called "glow-in-the-dark" paint. It is made from phosphors such as silver-activated zinc sulfide or doped strontium aluminate, and typically glows a pale green to greenish-blue color. The mechanism for producing light is similar to ...