Triple energy transfer and color tuning in Tb3+ and Eu3+-coactivated apatite-type gadolinium-containing phosphors

The triple energy transfer phenomenon of Gd3+→Tb3+, Gd3+→Eu3+, and Tb3+→Eu3+ in Sr3Gd(1-m-n)Na(PO4)3F:mTb3+,nEu3+ phosphors have been validated.236