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This effect was initially thought related to elevated temperatures. Scientists proved the opposite is true: though the life of an LED is shortened, the efficiency droop is less severe at elevated temperatures. [13] The mechanism causing efficiency droop was identified in 2007 as Auger recombination. [14] [15]
Negative luminescence is most readily observed in semiconductors.Incoming infrared radiation is absorbed in the material by the creation of an electron–hole pair.An electric field is used to remove the electrons and holes from the region before they have a chance to recombine and re-emit thermal radiation.
Whereas the term "fluorescence" tended to refer to luminescence that ceased immediately (by human-eye standards) when removed from excitation, "phosphorescence" referred to virtually any substance that glowed for appreciable periods in darkness, sometimes to include even chemiluminescence (which occasionally produced substantial amounts of heat).
Luminescence is a spontaneous emission of radiation from an electronically or vibrationally excited species not in thermal equilibrium with its environment. [ 1 ] A luminescent object emits cold light in contrast to incandescence , where an object only emits light after heating. [ 2 ]
This is a list of sources of light, the visible part of the electromagnetic spectrum.Light sources produce photons from another energy source, such as heat, chemical reactions, or conversion of mass or a different frequency of electromagnetic energy, and include light bulbs and stars like the Sun. Reflectors (such as the moon, cat's eyes, and mirrors) do not actually produce the light that ...
Triboluminescence of nicotine L-salicylate. Triboluminescence is a phenomenon in which light is generated when a material is mechanically pulled apart, ripped, scratched, crushed, or rubbed (see tribology).
Dexter (also known as Dexter exchange or collisional energy transfer, colloquially known as Dexter Energy Transfer) is another dynamic quenching mechanism. [12] Dexter electron transfer is a short-range phenomenon that falls off exponentially with distance (proportional to e −kR where k is a constant that depends on the inverse of the van der Waals radius of the atom [citation needed]) and ...
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.