Patent ID: 7288215

Claim:
A method of making a narrow-band UVB-emitting phosphor having a composition represented by a general formula (Y 1-x-y-z Gd x Ce y Pr z )MgB 5 O 10 where x has a value in a range from 0.02 to 0.80, y has a value in a range from 0.01 to 0.97, and z has a value in a range from 0 to 0.05 and x+y+z<1, the method comprising: (a) dissolving a source of Y, Gd, Ce, and optionally Pr, in an acidic solution; (b) adding ammonium hydroxide to form a hydroxide co-precipitate containing Y, Gd, Ce, and optionally Pr, from the acidic solution; (c) firing the hydroxide co-precipitate to form an oxide co-precipitate; (d) combining the oxide co-precipitate with magnesium oxide and boric acid to form a mixture; and (e) firing the mixture twice in a slightly reducing atmosphere to form the phosphor.