Phosphors:
The luminescent crystal which exhibits phosphorescence are called phosphors. There are different kinds of luminescent crystals which exhibit the phosphorescence.
Among these various phosphors, the phosphors used for CRO screens are
Applications of phosphors:
The luminescent crystal which exhibits phosphorescence are called phosphors. There are different kinds of luminescent crystals which exhibit the phosphorescence.
- Zns and CdS activated with Cu, Mn, Ag, Au etc.,
- Alkali halides activated with thalium.
- Compounds with luminescence in the pure form such as gadolinium sulphate, manganous halides, molybdates etc.,
- Oxide phosphors such as self activated ZnO and activated with transition metals.
- Silicate phosphors such as Zinc ortho silicate activated with divalent manganese.
- Organic crystals such as anthrascence activated with naphthalene.
Among these various phosphors, the phosphors used for CRO screens are
- Zinc-ortho silicate for green will be used in CRO tubes for general purpose.
- Calcium-tungstate for blue will be used in CRO tubes for fast photography.
- Zinc-cadmium sulphate for white will be used TV receiver tubes.
- Zinc-sulphate activated with Ag is used in colour television for Blue colour.
- Zinc-cadmium sulphide activated with copper is used in colour television for green colour.
- Yttrium oxysulphide activated with Europium and terbium is used in colour televisions for red colour.
Applications of phosphors:
- Fluorescent.
- Cathode ray oscilloscope.
- Television
- Radar
- Nuclear and radiation detectors
- Scintillation counters.
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