Phosphor for Blue LED to White Light Conversion
Lorad scientists have developed a modified cerium doped YAG phosphor that is an excellent candidate for the conversion of a 465nm emitting Blue LED to emit white light. Shown below, is a typical emission spectrum of the modified YAG when excited by 465nm emitting Blue LED.
Shown below is the emission spectrum of one composition of YAG:Ce such that the peak emission is 560nm.
By varying the concentration of the phosphor in the polymer matrix, the 465nm emission and 560nm emissions can be balanced. The 465nm will decrease and the 560nm increase such that at an appropriate concentration for a specific type of Blue emitting LED, chromaticity coordinates can be achieved to yield an efficient white emitting device. By selecting the correct quantity of phosphor and/or modifying its composition, it is possible to produce different color temperatures. This phosphor can be modified to work efficiently with different wavelength emitting phosphors, (430nm through 465nm). In addition YAG type phosphors are extremely environmentally and temperature stable, non hazardous and do not require expensive and poorly working coatings such as the strontium thiogallates. Our YAG type phosphors are an extremely cost competitive option compared to thiogallates and many of the newer phosphors.
This product is custom synthesized in our St. Petersburg facility. It is available in commercial quantities.