Concentration-dependent fluorescence decay and energy transfer in Cr3+ and Nd3+ co-doped Y3Al5O12 ceramic powder

Abstract

Energy transfer from Cr³⁺ to Nd³⁺ in Cr³⁺ and Nd³⁺ co-doped Y₃Al₅O₁₂ (Nd/Cr:YAG) was investigated by measuring the decay curves of Nd³⁺ and Cr³⁺ fluorescence for Cr:YAG and Nd/Cr:YAG ceramic powder samples that were produced by the sol–gel method in a Cr³⁺ concentration range of 0.1–6.0mol%. The energy transfer processes in Nd/Cr:YAG could be explained based on dipole–dipole interactions even when the concentration quenching of Cr³⁺ was included, and the experimental fluorescence decay characteristics of Nd³⁺ excited through Cr³⁺ were consistent with the theoretical predictions based on dipole–dipole interactions. For a high-quality Nd/Cr:YAG ceramic with negligible concentration quenching, the energy transfer efficiency from Cr³⁺ to Nd³⁺ increased with an increase in Cr³⁺ concentration.