Abstract: A phosphor in the form of a columnar powder capable of exhibiting enhanced luminous efficiency, providing various luminous colors by electron excitation depending on the selection of elements added thereto and having improved life characteristics. The phosphor is made by heating a starting material constituted by a GaN based phosphor material to a temperature equal to or greater than a sublimation temperature thereof. The phosphor thus obtained is represented by Ga1−xInxN:A,B, wherein x is larger than or equal to 0 and smaller than 1 (0≦x<1), A is Zn or Mg, and B is Si or Ge.

Abstract: A method for preparing a gallium nitride phosphor which is capable of emitting light at luminance increased to a degree sufficient to permit the phosphor to be practically used. A dopant compound containing elements reacted with H2 and gasified by heating is arranged on an upstream side in a calcination oven in which NH3 is flowed and a matrix element compound is arranged on the downstream side therein, resulting in calcination of the compound being carried out. This permits GaN to be surrounded with ammonia and the dopant during the calcination, so that the GaN phosphor may be fully doped with the dopant.