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, Cs2NaErCl6 double perovskite was synthesized via a hydrothermal method. The pressure-dependent photoluminescence (PL) lifetime of Er3+ in the range of 0-20 GPa was investigated, demonstrating its potential for pressure monitoring. The high-pressure relative sensitivity (SR) 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 Er3+ across a temperature range of 100-660 K, with a maximum SR of 5.36% K-1. By combining MXene with Cs2NaErCl6 and recording the FIR of Cs2NaErCl6 under 1550 nm excitation, the photothermal conversion temperature of MXene can be accurately determined. These findings highlight the potential of Cs2NaErCl6 for remote pressure and temperature sensing, particularly in the biomedical field.