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 Mn2+‐activated NaY9(SiO4)6O2 red‐emitting phosphors with splendid pressure sensing performances are developed. Excited by 408 nm, the resulting products emit bright red emission originating from 4T1(4G) → 6A1 transition of Mn2+, 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 (dλ/dP) 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/dP) 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.

Multicolor and multimodal luminescence in an Er3+ single-doped double perovskite for advanced anti-counterfeiting and encryption

“…The diffuse reflectance of the samples was measured and converted using the Kubelka–Munk function: 40 F ( R ) = (1 − R ) 2 /2 R and the [ F ( R ∞ ) hv ] 2 versus hv plots were made in accordance with the following function: 40 F ( R ∞ ) hv = A ( hv − E g ) n where R , hv , and A are the reflection coefficient, photon energy, and a constant, respectively, and n = 1/2 since NGTAO is a direct semiconductor. 41 The intercept of a fitted straight line was used to calculate the band gap energy for each sample (Fig. S3a and S3b†).…”

Enhanced VIS-NIR emission of Re4+ doped Cs2ZrCl6 for optical thermometry and near-infrared illumination applications

“…9(a). The temperature-dependent luminescence intensity ratio (LIR) of the thermal coupling levels (TCLs) can be described as follows: 52 LIR = A exp(−Δ E / kT ) + C where A is a constant, Δ E represents the energy difference between the two coupled levels, T signifies temperature, k denotes the Boltzmann factor, and C is another constant. As the temperature increases, the I anti-S / I S value, as a function of T , fits well with eqn (5), yielding a fitting parameter Δ E of 214 meV.…”

A highly sensitive lifetime-based luminescent manometer and bi-functional pressure–temperature sensor based on a spectral shift of the R-line of Mn4+ in K2Ge4O9

“…As a response to this demand lifetime-based luminescent manometers based on materials doped with transition metal (TM) ions have been recently proposed. 18,19,29–32 Due to the unique electronic configuration of TM ions, their spectroscopic properties exhibit high sensitivity to the changes in the local environment of the ions. In general, the compression of the phosphor induces a change in the strength of the crystal field acting on these ions.…”