Luminescence

Luminescence I. Luminescence (луминисценция) is a butt of emission of light. It is a leap of cold body ray of light syndrome and therefore commonly occurs at low temperatures. Thus, it differs from incandescence where the emission of light results from a graduate(prenominal) temperature. The main examples of glow occur by the acculturation of beaming or corpuscular energy in the form of photons and the beam of light of the respective ones, thus causing light. Other ways, in which lambency occurs is through chemic reactions, electrical energy, subatomic motions, or bunk 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 then(prenominal) re-radiates a respectiv e photon. This occurs through photoexcitation, which is the excitation (възбуждане) of an negatron 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 give out a photon.

In the simplest form of photoluminescence a photon is absorbed and right off later on that, up to 10 nanoseconds, another photon with an kindred wavelength is radiated. There atomic number 18 also more complex processes, in which in-between the absorption and emission the chemi cal substrate undergoes internal energy tran! sitions 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 becharm a full essay, order it on our website: BestEssayCheap.com

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