Sialon phosphor

1. A SiAlON phosphor represented by a general formula (2)

Lu p Si 12−(m+n) Al (m+n) O n N 16−n :Eu q   (2)

wherein at least a main phase comprises an alpha SiAlON crystal structure;

wherein m is a numerical value represented by 3×k, and n is a numerical value represented by (3×k)/2, assuming that p+q is k; and

wherein 0.25≦p≦0.65 and 0.03≦q≦0.08.

2. The SiAlON phosphor as claimed in claim 1 , wherein 0.25≦p≦0.35.

3. The SiAlON phosphor as claimed in claim 1 , wherein 0.30≦p≦0.65.

4. A light emitting device comprising:

the SiAlON phosphor as claimed in claim 1 , and

a semiconductor blue light emitting diode element.

5. A light emitting device comprising:

the SiAlON phosphor as claimed in claim 2 , and

a semiconductor blue light emitting diode element.

6. A light emitting device comprising:

the SiAlON phosphor as claimed in claim 3 , and

a semiconductor blue light emitting diode element.