This invention relates to phosphor compositions, and in particular to phosphor compositions excited by ultraviolet radiation to emit in the red region of the visible spectrum.
Europium activated yttrium oxide (YOE) is a well known red emitted phosphor. It is used in many devices such as cathode ray tubes and lamps. This phosphor though is quite expensive for large-scale use, especially in lamps. Other red-emitting phosphors are known, such as, calcium yttrium borate described by the formula CaYBO.sub.4 :Eu as disclosed by G. Blasse in The Journal Of Solid State Chemistry, Vol. 4, page 52, 1972. A problem with this phosphor is that its efficiency of photoluminescence under excitation by 254 nanometer ultraviolet is about 40% of the YOE phosphor, which is insufficient for lamp use.