Super-sensitive multi-modal optical manometer based on huge pressure-induced spectral red-shift and broadening of Mn2+ emission band in green-emitting Zn2GeO4 phosphors

To overcome the small sensitivities of luminescent manometers, Mn2+-activated Zn2GeO4 green-emitting phosphors with admirable manometric characteristics were synthesized. The structural stability of the studied samples is theoretically and experimentally investigated. Moreover, as pressure elevates, a huge spectral red-shift and a broadening of the emission band are observed in studied samples, contributing to color-tunable luminescence, i.e. from green to yellow, and ultimately to orange-red. Specifically, when pressure increases to 6.76 GPa, the emission band centroid shifts from 535.9 to 634.9 nm, leading to a superior sensitivity of dλ/dp = 21.3 nm/GPa. Whereas, in the same operating pressure range, the full width at half maximum (FWHM) of the emission band rises from 32.3 to 102.9 nm, resulting in unprecedentedly high sensitivity of dFWHM/dp = 17.0 nm/GPa. Furthermore, through analyzing the pressure-dependent color coordinates, a maximum sensitivity of 29.43% GPa-1 is achieved, when x-coordinate is adopted. Additionally, the applicability of the developed manometer is confirmed by a simple uniaxial pressure experiments to showcase its practical use in industrial and daily-life purposes. Notably, the designed sensor exhibits the highest pressure sensitivities reported to date in different modes, namely, emission band centroid, FWHM and color coordinate, making supersensitive multimodal optical manometry a reality.为解决发光测压计灵敏度偏低的痛点，本研究合成了具备优异测压性能的锰离子（Mn²⁺）掺杂锗酸锌（Zn₂GeO₄）绿色发光荧光粉。对所制备样品的结构稳定性开展了理论与实验双重表征分析。进一步研究发现，随着压力升高，目标样品的发射光谱呈现显著红移与发射谱带展宽现象，可实现可调谐发光：即从绿色逐步过渡为黄色，最终转变为橙红色。具体而言，当压力升至6.76 GPa时，发射峰质心波长从535.9 nm偏移至634.9 nm，对应的灵敏度系数dλ/dp达21.3 nm/GPa，性能优异。在相同压力区间内，发射峰半高全宽（full width at half maximum, FWHM）从32.3 nm增至102.9 nm，其灵敏度系数dFWHM/dp高达17.0 nm/GPa，灵敏度前所未有。此外，通过分析压力依赖的色坐标参数，当采用x坐标时，最大灵敏度可达29.43% GPa⁻¹。本研究还通过简易单轴压力实验验证了所开发测压计的实用性，展示了其在工业与日常场景中的应用价值。值得注意的是，本设计的传感器在发射峰质心、半高全宽及色坐标三种检测模式下，均实现了迄今已报道的最高压力灵敏度，使得超高灵敏度多模态光学测压技术真正落地成为可能。