Photoluminescence investigation of certain rare earth Eu3 y3 Sm3 Pr3 ions activated eulytite type phosphate based phosphors

Abstract

Recently, the Solid State Lighting (SSL) are used in day to day life of our developing countries. This solid state lighting is essential in our daily life because they are used in various types of lamps, mobile displays, TVs, Signals, CRT, etc. Light is a form of electromagnetic energy and to produce the light another form of energy must be supplied. The first commercially available white LEDs were developed by Nichia Corporation using InGaN blue LED chip with the yellow emitting Y3Al5O12:Ce3+ phosphor. The drawbacks of this Y3Al5O12:Ce3+ based WLEDs are poor colour rendering index and high correlated colour temperature. Nowadays, the inorganic solid newlinestate Light Emitting Diodes (LEDs) are used as potential candidates for lighting technologies. The solid state lighting related research is more useful for the scientific and industrial fields, because the SSL materials have high luminous efficiency, environment friendliness, small volume, energy savings, and long life. Generally, the phosphor materials are classified as different groups, such as silicates, phosphates, borates, sulphates, fluorides, oxides, vanadate and nitrides etc. The rare earth ions Eu3+, Sm3+, Dy3+, Pr3+, Tb3+, Ce3+ when incorporated in the above mentioned hosts can produce White Light Emitting Diodes (WLEDs). These rare earth ions sometimes act as sensitizers and/or activators, depending on the various host matrices which leads to interesting spectroscopic properties. Recently, the rare earth ions activated phosphate based phosphors have gained much attention for solid state lighting because of their structural stability, high luminescence, high thermal and chemical stability and mechanical stability. Due to these advantages the phosphate based phosphors are considered as potential candidates for solid state lighting applications. Present thesis is to find novel phosphors for solid state lighting and display applications. newline newline