Size-dependent polarized photoluminescence from Y₃Al ₅O₁₂: Eu³⁺ single crystalline nanofiber prepared by electrospinning

After one-step calcination of the as-prepared electrospun nanofibers, single crystalline YAG (Y₃Al₅O₁₂) nanofibers were successfully synthesized in situ even when the diameter reached 800 nm. X-Ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) results confirmed that the calcined YAG nanofibers were pure body-centered cubic (bcc) YAG phase. The crystallography of single crystalline YAG nanofibers was perfect. After doping with Eu³⁺ ions, notable polarized photoluminescence (PL) was observed from an individual YAG: Eu ³⁺ nanofiber, which was predominately owing to the dielectric mismatch between the nanofiber and its surroundings. The PL polarization ratio (ρ) showed a strong diametrical dependence as a factor of ∼1/R when the diameter (R) is comparable to the light wavelength. The large scale, super-long, single crystalline YAG nanofibers with notable polarized PL are promising to be applied as one dimensional nanofiber lasers, linearly polarized light resources, polarized sensors, photodetectors, etc.