Research on optical performance of Ln2O2S:Er3+/Yb3+ (Ln = La/Gd/Y) phosphors based on different phonon energies

It is crucial to explore the intrinsic mechanisms that influence thermometric sensitivity. This study investigates the optical performance of materials with the same crystal structure but different phonon energies. Ln2O2S:Er3+/Yb3+ (Ln = La/Gd/Y) phosphors with similar morphology and particle sizes were prepared to systematically study the influence of different phonon energy matrices on optical properties. The intrinsic mechanism was elucidated through the matching degree between the energy gap and phonon energy, Judd–Ofelt (J–O) theory, and quantum dielectric theory. It was ultimately concluded that the combination of high phonon energy with a large Ω2 and a small Ω6 is beneficial for enhancing the sensitivity of temperature sensing materials.