Luminescencethat

Luminescencethat refers to the phenomenon of luminescence, which is the emission of light by a substance not resulting from heat. This light is "cold light," meaning that less than 20% of the emitted light is visible light. Luminescence is a broad term that encompasses several types of light emission, each triggered by different forms of energy.

One common form is photoluminescence, where a substance absorbs photons (light energy) and then re-emits photons at a longer wavelength. Fluorescence and phosphorescence are sub-types of photoluminescence. Fluorescence occurs when the re-emission of light happens almost instantaneously after absorption, while phosphorescence involves a delay, causing the substance to glow for some time after the excitation source is removed.

Chemiluminescence is another type, where light is produced through a chemical reaction. Bioluminescence, a subset of chemiluminescence, is light produced by living organisms, such as fireflies or certain deep-sea creatures. Thermoluminescence involves the release of light when a previously irradiated material is heated, and electroluminescence is the emission of light in response to an electric current or field. Triboluminescence is the generation of light when a material is mechanically stressed, rubbed, or broken. Understanding luminescencethat allows for applications in areas like lighting, medical imaging, and scientific research.