Red photoluminescence due to energy transfer from Eu2+to Cr3+in Sr3Al10SiO20–SrAl12O19mixed phases

Sr3Al10SiO20–SrAl12O19, doped with Eu 2+ ,C r 3+ and (Eu 2+ +C r 3+ ) is prepared by solid-state reaction and energy transfer from Eu 2+ to Cr 3+ in the phase of Sr3Al10SiO20 is the focus of investigation. The spectrum of Sr3Al10SiO20–SrAl12O19 :E u 2+ shows f–d emission bands at 460 and 400 nm. Cr 3+ doped Sr3Al10SiO20–SrAl12O19 yields emission lines at 688 and 696 nm and a broad emission band between 650 and 750 nm. The photoluminescence study and fluorescence lifetime measurements demonstrate efficient energy transfer from Eu 2+ to Cr 3+ in Sr3Al10SiO20 :E u 2+ ,C r 3+ . The emission lines peak at 688 nm and 696 nm, which, respectively, originate from 2 E– 4 A2 transitions in the phases of SrAl12O19 and Sr3Al10SiO20. The broad emission band of Cr 3+ between 650 and 750 nm in the phase of Sr3Al10SiO20 is considered to be the 4 T2– 4 A2 transition by calculating the strength of the octahedral crystal field Dq, the Racah parameters B and C as well as by constructing the Tanabe–Sugano diagram.