Luminescence

Luminescence I. Luminescence (луминисценция) is a butt of emission of light. It is a leap of cold body radiation sickness syndrome and therefore unremarkably occurs at low temperatures. Thus, it differs from incandescence where the emission of light results from a graduate(prenominal) temperature. The main tokens of glow occur by the acculturation of wide or corpuscular energy in the form of photons and the radiation of the respective ones, thus causing light. Other ways, in which radiance occurs is through chemical reactions, electrical energy, subatomic motions, or pass off on a crystal. II. Types of luminescence 1. Photoluminescence (фотолуминисценция) is one of the main types of luminescence. In this process a specific substance absorbs a photon and hence re-radiates a respective pho ton. This occurs through photoexcitation, which is the excitation (възбуждане) of an electron to a high energy state in the substance by the engrossment of the particular photon. Afterwards the electron goes through electron simplicity and returns to the lower energy state by radiate a photon.

In the simplest form of photoluminescence a photon is absorbed and straight off later on that, up to 10 nanoseconds, another photon with an akin wavelength is radiated. There atomic number 18 also to a greater extent complex processes, in which in-between the absorption and emission the chemical substrate undergoes internal energ! y transitions and the prison term for the radiation of a photon, becomes longer and the photon itself has a different wavelength. 2. Fluorescence (флуоресценция) is a type of photoluminescence, in which the photon, released by the substance, has a longer wavelength than the wavelength of the photon initially...If you fatality to contain a full essay, order it on our website: BestEssayCheap.com

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