Optical Thermometry Based on Up‐Conversion Luminescence Behavior of Er3+ ‐Doped Transparent Sr2YbF7 Glass‐Ceramics

Abstract

Transparent novel glass‐ceramics containing Sr2YbF7:Er3+ nanocrystals were successfully fabricated by melt‐quenching technique. Their structural and up‐conversion luminescent properties were systemically investigated by XRD, HRTEM, and a series of spectroscopy methods. The temperature‐dependent up‐conversion spectra prove that 2H11/2 and 4S3/2 levels of Er3+ are thermally coupled energy levels (TCEL). Consequently, the 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 emissions of Er3+ in Sr2YbF7:Er3+ glass‐ceramics can be used as optical thermometry based on fluorescence intensity ratio (FIR) technique. Combined with low phonon energy and high thermal stability, Er3+ ions in Sr2YbF7 glass‐ceramics present broad operating temperature range (300–500 K), large energy gap of TCEL (786 cm−1) and high theoretical maximum value of relative sensitivity (62.14 × 10−4 K−1 at 560 K), which suggests that Sr2YbF7:Er3+ glass‐ceramics may be excellent candidates for optical temperature sensors.