Optical thermometry based fluorescence intensity ratio in Y2Mg2Al2Si2O12:Bi3+,Eu3+ phosphors

Highlights: • The preparation technology of Y₂Mg₂Al₂Si₂O₁₂:Bi³⁺,Eu³⁺ phosphors is simple. • The main emission peak of Eu³⁺ and emission band of Bi³⁺ are well separated. • Y₂Mg₂Al₂Si₂O₁₂:Bi³⁺,Eu³⁺ phosphors exhibit excellent thermal stability. • Relative sensitivity S_r accelerates with rising temperature. -- Abstract: An array of Y₂Mg₂Al₂Si₂O₁₂:Bi³⁺,Eu³⁺ phosphors were successfully manufactured. The crystal phase, microscopic image and optical properties were systematically surveyed with X-ray diffraction patterns, scanning electron microscopy and fluorescence spectra, respectively. Under 282 nm excitation, for Y₂Mg₂Al₂Si₂O₁₂:Bi³⁺ phosphors, a broadband emission center located at 319 nm was observed, which is derived from the ³P₁ → ¹S₀ transition. For Bi³⁺/Eu³⁺ co-doped samples, besides the 319 nm emission of Bi³⁺, a range of characteristic sharp lines of Eu³⁺ were observed. Meanwhile, the maximum efficiency of energy transfer (Bi³⁺ → Eu³⁺) can arrive to 89.5%. According to the emission spectra at different temperature, the samples present an excellent temperature sensing property based on fluorescence (from Bi³⁺ and Eu³⁺) intensity ratio and thermal stability. The maximum relative sensitivity S_r reaches to 0.544 %K⁻¹ at 573 K. The emission intensity at 483 K maintains 95.5% of that at 303 K. All above meaningful results indicate that the samples may have certain application value in the field of temperature measurement.