Suppressed energy transfer between different rare earth ions to obtain enhanced and tuned fluorescence by using Janus nanofibers

Abstract

Here, we put forward a viewpoint that the energy transfer between different rare earth (RE) ions creates negative effects in RE ion doped white fluorescent materials when the native fluorescence intensity of the energy donor is weaker than that of the receptor as the natively weak emission from the donor, the decisive factor for white fluorescence, is further weakened by the energy transfer. The solution for suppressing the energy transfer between different RE ions is also proposed. As an example, Dy³⁺/Eu³⁺ codoped Gd₂O₃ Janus nanofibers emitting white fluorescence are constructed. Because Dy³⁺ and Eu³⁺ are separated in the Janus nanofibers, the energy transfer from Dy³⁺ to Eu³⁺ is effectively suppressed. Therefore, natively weak blue emission from Dy³⁺ is hardly further weakened by the energy transfer, and enhanced white fluorescence is achieved. Our proposed idea provides new insights into designing other RE doped fluorescent materials.