Pressure‐Induced Remarkable Spectral Red‐Shift in Mn2+‐Activated NaY9(SiO4)6O2 Red‐Emitting Phosphors for High‐Sensitive Optical Manometry

Abstract To settle the low sensitivity of luminescent manometers, the Mn 2+ ‐activated NaY 9 (SiO 4 ) 6 O 2 red‐emitting phosphors with splendid pressure sensing performances are developed. Excited by 408 nm, the resulting products emit bright red emission originating from 4 T 1 ( 4 G) → 6 A 1 transition of Mn 2+ , in which the optimal concentration of the activator ion is ≈1 mol%. Moreover, the admirable thermal stability of the developed phosphors is studied and confirmed by the temperature‐dependent emission spectra, based on which the activation energy is derived to be 0.275 eV. By analyzing the pressure‐dependent Raman spectra, the structural stability of the synthesized compounds at extreme conditions is verified. Furthermore, the designed phosphors exhibit remarkable spectral red‐shift at elevated pressure. Especially, as pressure increases from 0.75 to 7.16 GPa, the emission band centroid shifts from 617.2 to 663.4 nm, resulting in a high sensitivity (d λ /d P ) of 7.00 nm GPa −1 , whereas the full width at half maximum (FWHM) increases from 83.0 to 110.6 nm, leading to the ultra‐high sensitivity (dFWHM/d P ) of 10.13 nm GPa −1 . These achievements manifest that the designed red‐emitting phosphors are appropriate for ultrasensitive optical manometry. More importantly, the developed manometer is a current global leader in sensitivity, when operating in the band‐width mode, that is, FWHM.