Energy Transfer in Mixed Lanthanides Complexes: Toward High‐Performance Pressure Sensors Based on the Luminescence Intensity Ratio

Abstract In this study, a reversible pressure‐sensing material with high sensitivity is presented. Mixed β‐diketonate complexes of Tb 3+ and Eu 3+ [(Ln)(acac) 3 phen] are synthesized with phenanthroline as an ancillary ligand. The organic ligands provide the antenna effect to make the Ln 3+ complex excitable at 405 nm. Eu 3+ emission results from efficient energy transfer (ET) from Tb 3+ . Under 405 nm excitation, the emission intensity of Tb 3+ decreases whereas the emission intensity of Eu 3+ increases with pressure, making this complex a potential pressure sensor based on luminescent‐intensity‐ratio (LIR) up to 700 MPa. This study then discusses the application of this Tb 3+ /Eu 3+ complex for pressure sensing depending on measurement conditions. The addition of the optically neutral ion Y 3+ to the system can reduce the impact of pressure‐induced structural defects on the emission, thus improving the reversibility of the LIR variation as a function of pressure. Therefore, a self‐calibrating, reliable, and reversible pressure‐sensing material is proposed here, with remarkable pressure sensitivity compared to a peak shift‐based pressure sensor.