Method of making blue emitting aluminate phosphor for VUV excited light emitting device

A divalent europium activated alkaline earth aluminate phosphor complex having the empirical formula:

• (AE2-x-yLaxEuy)Al10O17
• wherein 0≦x≦1;
• 0.01≦y≦0.1;
• La is lanthanum;
• Eu is divalent europium;
• Al is aluminum;
• AE is alkaline earth metal selected from the group consisting of Ba, Sr, Ca, Mg;
• wherein said phosphor complex exhibits the following luminescent and morophological properties:
• relative intensity (AU) at 147 nm excitation from about 90 to about 100 and relative intensity (AU) at 173 nm excitation from about 90 to about 105 with half width from about 53 to about 55 nm;
• color coordinates of x from about 0.1535 to about 0.1612 and y from about 0.0715 to about 0.0805;
• and particle size from about 0.05 microns to about 3.0 microns.

A divalent europium activated alkaline earth aluminate phosphor complex having the empirical formula:

• (AE2-x-yLaxEuy)Al10O17
• wherein 0≦x≦1;
• 0.01≦y≦0.1;
• La is lanthanum;
• Eu is divalent europium;
• Al is aluminum;
• AE is alkaline earth metal selected from the group consisting of Ba, Sr, Ca, Mg;
• wherein said phosphor is prepared by a method comprising the steps of:
• contacting in an aqueous acidic solution, an organic precursor providing a source of aluminum, a source of alkali earth metal, a source of europium, and optionally a source of lanthanum to form a gel;
• converting said gel into a gel powder;
• and
• thermally decomposing said gel at a temperature below a solid state reaction temperature to produce said phosphor complex.