Luminescence

Luminol and haemoglobin, an example of chemiluminescence
UV-photoluminescence in microbiological diagnostics

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] Generally, the emission of light is due to the movement of electrons between different energy levels within an atom after excitation by external factors. However, the exact mechanism of light emission in vibrationally excited species is unknown.

The dials, hands, scales, and signs of aviation and navigational instruments and markings are often coated with luminescent materials in a process known as luminising.[3]

  1. ^ Chemistry (IUPAC), The International Union of Pure and Applied. "IUPAC - luminescence (L03641)". goldbook.iupac.org. Retrieved 2023-12-03.
  2. ^ Valeur, Bernard; Berberan-Santos, Mário N. (2011-06-01). "A Brief History of Fluorescence and Phosphorescence before the Emergence of Quantum Theory". Journal of Chemical Education. 88 (6): 731–738. Bibcode:2011JChEd..88..731V. doi:10.1021/ed100182h. ISSN 0021-9584.
  3. ^ Cooper, John R.; Randle, Keith; Sokhi, Ranjeet S. (2003). Radioactive Releases in the Environment: Impact and Assessment. Wiley. p. 192. ISBN 978-0-471-89924-2.