Pressure-induced phase evolution and anti-pressure quenching luminescence in Pt4+-doped Cs2ZrCl6 double perovskites for highly sensitive multi-parameter optical manometry

Pt 4+ -doped Cs 2 ZrCl 6 double perovskites were synthesized through a rapid room-temperature synthetic approach. Excited by 365 nm, the obtained compounds exhibit intense red photoluminescence, originating from self-trapped exciton emission. In-situ high-pressure absorption spectroscopy was employed to analyze the pressure-driven evolution of the optical band gap. Moreover, high-pressure X-ray diffraction and Raman spectroscopy experiments indicate a pressure-induced phase transition at around 24 GPa. With compression from 0.27 GPa to 41.56 GPa, the synthesized samples not only exhibit a distinct spectral blue shift but also show enhanced luminescence intensity, leading to the multicolor emission and high-pressure zero-quenching luminescence behavior. Furthermore, the occurrence of the pressure-induced phase transition is visible from the changes in the full width at half maximum (FWHM) of the emission band, which first decreases and then increases with compression, reaching a minimum value at 24.32 GPa. Such strong changes of the emission band centroid and FWHM were employed as the manometric parameters, with maximum absolute sensitivities of 5.35 nm GPa −1 and 2.19 nm GPa −1 , respectively. Additionally, the developed compounds exhibit colorimetric pressure sensing with a maximum relative sensitivity of 2.32% GPa −1 . These findings highlight that the Pt 4+ -doped Cs 2 ZrCl 6 double perovskites hold great potential for multi-parameter, wide-operating range, and high-sensitivity visual pressure sensors.