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 (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 Er3+ across a temperature range of 100–660 K, with a maximum S
R 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.