Exploring the Potential Applications of Lanthanide-Based Double Perovskite in Remote Pressure and Temperature Sensing.

Remote optical sensing with nondestructive, fast, and accurate detection capabilities is a powerful noncontact method widely used in natural, industrial, and biological fields. In this work, Cs 2 NaErCl 6 double perovskite was synthesized via a hydrothermal method. The pressure-dependent photoluminescence (PL) lifetime of Er 3+ in the range of 0-20 GPa was investigated, demonstrating its potential for pressure monitoring. The high-pressure relative sensitivity ( S R ) is ∼18.45% GPa -1 . Temperature measurements were conducted using the fluorescence intensity ratio (FIR) of the thermal couple energy level (TCEL) and the nonthermal couple energy level (NTCEL) of Er 3+ across a temperature range of 100-660 K, with a maximum S R of 5.36% K -1 . By combining MXene with Cs 2 NaErCl 6 and recording the FIR of Cs 2 NaErCl 6 under 1550 nm excitation, the photothermal conversion temperature of MXene can be accurately determined. These findings highlight the potential of Cs 2 NaErCl 6 for remote pressure and temperature sensing, particularly in the biomedical field.