abstract |
A certain aspect of the present invention is a phosphor powder comprising α-sialon phosphor particles containing Eu. The phosphor powder has an internal quantum efficiency of P1 after holding at 600° C. for 1 hour in an atmospheric atmosphere, and P2 when an internal quantum efficiency after holding at 700° C. in an atmospheric atmosphere for 1 hour, P1 is 70% or more. , and (P1-P2)/P1×100 is 2.8% or less. |