Tunable Multicolor Luminescence, Full‐Spectrum White‐Light Emission and Optical Temperature Sensing Based on Bi ³⁺ , Tb ³⁺ and Eu ³⁺ Doped Y ₄ Al ₂ O ₉ Nanofibers

Abstract The realization of tunable multicolor luminescence especially full‐spectrum white‐light emission in a single matrix has aroused more attention from researchers. To address the above challenge, Bi 3+, and Tb 3+ are selected as both activators and sensitizers with the help of energy level matching engineering of Bi 3+ and Tb 3+ having matching energy levels with Eu 3+ , a series of 1D Y 4 Al 2 O 9 :Bi 3+ , Bi 3+ /Eu 3+ , Tb 3+ , Tb 3+ /Eu 3+ and Bi 3+ /Tb 3+ /Eu 3+ nanofibers (NFs) are designed and synthesized by a simple electrospinning technique combined with an oxidative calcination. Under 298‐nm UV light excitation, Y 4 Al 2 O 9 :Bi 3+ /Tb 3+ /Eu 3+ NFs demonstrate tunable multicolor luminescence (blue, purple, red, green, yellow, and white) especially full‐spectrum white‐light emission via double energy transfer (ET) effect and modulation of molar ratio among Bi 3+ , Tb 3+ and Eu 3+ . Additionally, Y 4 Al 2 O 9 :3%Bi 3+ /7%Tb 3+ /1%Eu 3+ NFs are sensitive to temperature, and the maximum S α and S γ values of Y 4 Al 2 O 9 :3%Bi 3+ /7%Tb 3+ /1%Eu 3+ NFs reach 0.0417 K −1 and 0.84% K −1 , respectively. In virtue of electrospinning, triple activators (Bi 3+ , Tb 3+ , and Eu 3+ ) are readily and uniformly doped in Y 4 Al 2 O 9 NFs single matrix to achieve dual function of tunable multicolor luminescence and temperature sensing. The formation principle and luminescence theory of the samples are clarified. The findings in this work are instructive to develop multicolor luminescent phosphors and temperature‐sensing materials.