Optimizing the crystal environment through extended x-ray absorption fine structure to increase the luminescent lifetimes of Er³⁺ doped Y₂O₃ nanoparticles Available to Purchase

To predict and optimize luminescence efficiency of rare-earth ion doped (RE) nanophosphors, a relationship between the RE-concentration and the luminescent parameters is often obtained by Judd-Ofelt analysis, where the quality factor (⁠$χ=Ω4/Ω6$⁠) depends on the Er interactions with other RE elements in the second nearest neighboring shell. In this work, a detailed analysis of the local bonding environment by extended x-ray absorption fine structure (EXAFS) analyses is shown as effective as the Judd-Ofelt analysis to quantify the Er↔RE interaction in the second nearest neighboring shell (⁠$ρN=IREr↔RE2/IREr↔RE1$⁠). As the physical basis of ρ_N is consistent to that of χ, the EXAFS analysis becomes a viable alternative to replace Judd-Ofelt analysis to predict the optimum dopant concentration. This approach was corroborated based on analysis of Er³⁺:Y₂O₃ and core-shell Er³⁺:Y₂O₃|Y₂O₃ (5 nm shell) nanoparticles (NPs), with Er³⁺ concentrations up to 20 mol %. The ρ_N ratio from EXAFS analysis was shown to strongly correlate to the lifetimes extracted from the Judd-Ofelt analysis, both predicting the optimal dopant concentrations to be at 5 mol % and 2 mol % for the Er³⁺:Y₂O₃ and core-shell NPs, respectively. This confirms that EXAFS analysis can be used as a more time efficient method to achieve the same outcome typically obtained by Judd-Ofelt analysis, enabling the optimization of the luminescent lifetimes of RE doped nano-phosphors.