Investigating the Potential of Cr3+-Doped Pyroxene for Highly Sensitive Optical Pressure Sensing

Luminescent manometry has gained significant popularity in recent years due to its capability to provide in situ pressure measurements in a remote manner. Therefore, there is a growing need to identify phosphors with pressure-dependent spectroscopic properties that can be utilized to develop highly sensitive pressure sensors operating over a wide pressure range. Hence, we present a novel temperature-invariant luminescent manometer based on Cr3+ ion emission in pyroxene Ca0.8Sr0.2MgSi2O6:Cr3+. We utilized two readout modes, including an innovative luminescent pressure sensing ratiometric approach based on the broad emission band associated with the 4T2g → 4A2g electronic transition of Cr3+ ions. This approach provided an exceptionally high sensitivity of SR = 50.7 ± 0.5% GPa–1 and ensured temperature-independent pressure measurements, thus offering highly reliable readouts. Furthermore, the proposed readout mode, which leverages changes in luminescence kinetics, demonstrated high sensitivity at high pressure at around 5 GPa (SR ∼ 8 ± 0.2% GPa–1) surpassing the performance of luminescence kinetics-based manometers reported to date. Consequently, Ca0.8Sr0.2MgSi2O6:Cr3+ emerges as a highly promising phosphor with significant application potential for pressure sensing across a broad pressure range.