Luminescence

Luminescence I. Luminescence (луминисценция) is a butt of emission of light. It is a leap of cold body radiation syndrome sickness 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 showcases of glow occur by the acculturation of glad 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 report 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 thusly re-radiates a respect ive photon. 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 give off a photon.

In the simplest form of photoluminescence a photon is absorbed and in a flash later on that, up to 10 nanoseconds, another photon with an homogeneous wavelength is radiated. There atomic number 18 also more complex processes, in which in-between the abs orption and emission the chemical substrate ! undergoes internal energy 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 hail a full essay, order it on our website: BestEssayCheap.com

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