High-pressure dual-mode optical manometry for visual pressure sensing using Ce3+-activated NaMgBO3 phosphors

To overcome the limitation of low sensitivity in optical pressure sensors, Ce³⁺-doped NaMgBO₃ phosphors have been synthesized via high-temperature solid-phase method. Density functional theory (DFT) calculations and absorption spectroscopy analysis demonstrate that the NaMgBO₃ crystal structure serves as an excellent host material for rare-earth ions luminescence. Upon 375 nm excitation, bright cyan emission from Ce³⁺ was observed. To assess the potential application in optical pressure sensing, the pressure-dependent photoluminescence spectra and Raman spectra of the NaMgBO₃:0.01Ce³⁺ sample were measured and analyzed in detail. As pressure increased from 0.31 to 17.18 GPa, the emission peaks shift from 469.3 to 496.1 nm, accompanied by a visible color transition from cyan to green, achieving the maximum sensitivity of 2.94 nm/GPa. Furthermore, quantitative evaluation of pressure sensitivity using chromaticity coordinates yields a maximum sensitivity of 6.22 % GPa⁻¹. These results demonstrate that Ce³⁺-doped NaMgBO₃ phosphors exhibit potential for optical manometry applications, where pressure-induced chromaticity shifts and spectral displacements enable dual-mode detection, thereby achieving high-precision pressure measurements across a broad operational range.