Thermal sensitivity of Ho³⁺ fluorescence in oxyfluoride nanocrystals and derivative embedded fibers

(Y_1-x-yHo_xYb_y)OF/polyacrylonitrile (YOF-H_uY_v/PAN) composite fibers prepared by electrostatic spinning have been demonstrated to possess effective upconversion (UC) luminescence and sensitive temperature feedback properties for laser display and real-time temperature monitoring in complex environments. When the excitation power density is increased to 73 mW/mm², the total luminous flux reaches 3.35 mlm, demonstrating that the Ho³⁺/Yb³⁺ co-doped YOF nanocrystals embedded in the composite fibers are efficient luminous materials. The quantum yields (QYs) of green and red emissions from Ho³⁺ are derived to be 2.97 × 10⁻⁵ and 1.40 × 10⁻⁵ respectively when the pump power density arrives at 73 mW/mm² under 977 nm laser, and the high photon generation efficiency ensures sufficient fluorescence intensity for tracing temperature feedback. The maximum relative sensitivities appear at 303 K, while the absolute sensitivity (S_A) and relative sensitivity (S_R) of the nanofibers retain 13.77% K⁻¹ and 0.34% K⁻¹ at 433 K respectively, demonstrating that the nanofibers have superior optical temperature sensing properties. The composite fibers with effective luminescence and high temperature sensitivity as luminescent materials provide a potential option for the field of laser display and temperature sensing.