Pr^{3+ 1}S₀→Cr³⁺ energy transfer and ESR investigation in Pr³⁺ and Cr³⁺ activated SrAl₁₂O₁₉ quantum cutting phosphor

With the help of the Dexter's theory, the energy transfer mechanism from Pr^{3+ 1}S₀ to Cr³⁺ is investigated theoretically in SrAl₁₂O₁₉:Pr³⁺, Cr³⁺ quantum cutting phosphors. The electron spin resonance (ESR) spectra of Pr³⁺ and Cr³⁺-doped SrAl₁₂O₁₉ with magnetoplumbite structure have been studied. The Cr³⁺ ion is found to enter the Al4(4f) site, which is very close to the Sr(2d) site replaced by the Pr³⁺ ions in the host. The theoretical results indicate that the efficient Pr^{3+ 1}S₀→Cr³⁺ energy transfer can only take place in the intermediate mirror planes, in which for the nearest and next-nearest Pr³⁺-Cr³⁺ pairs, both dipole-dipole and dipole-quadrupole interactions can play their parts in the transfer. Finally, an overview is given about the research on the energy transfer from Pr^{3+ 1}S₀ to codopants in their co-doped materials.