Solid state white light sources based on a nearUV LED chip are gaining more and more attention. This is due to the increasing efficiency of nearUVemitting LED chips and wider phosphors selection if compared to devices based on blue LED chips. Here, a brief overview is given of the concepts of generating white light employing nearUV LED and some optical properties of the available phosphors are discussed. Finally, the synthesis and optical properties of very efficient redemitting Ba2Y5B5O17:Eu3+ phosphor powder and ceramics is reported and discussed in terms of possible application as a red component in nearUV LEDbased white light sources.
Keywords: CIE 1931 colour coordinates; Eu3+; borate; ceramics; luminous efficacy; nearUV LED; quantum efficiency; red phosphor; thermal quenching.