“…It is known that even if we dope a phosphor material initially using an impurity salt consisting of the ions in a particular ionic state, it is not necessary that they would be incorporated inside the matrix in the same form, and they may get incorporated in different ionic states (if exists naturally). 101–103 For example, in the present study for doping Eu 3+ ions in a phosphor material, we used Eu(NO 3 ) 3 salt consisting of Eu 3+ ions, and it could be seen in the PL spectra ( Fig. 10 ), they have entered in both forms, Eu 3+ as well as Eu 2+ .…”