Energy transfer mechanisms in Tb3+-doped perovskite quantum dot germanium borate glass ceramics with enhanced luminescence efficiency

Abstract

In recent years, rare earth ion doping has enhanced the luminescence performance of perovskite quantum dot (PQD) glass, but the enhancement mechanism caused by internal energy transfer deserves further study. In this work, a series of CsPbBr₃ PQDs doped with different concentrations of Tb³⁺ ions was prepared in a germanium borate glass matrix by the traditional melt quenching method and a heat treatment process. The experimental results indicate that after introducing Tb³⁺ ions into the PQD glass, the photoluminescence intensity was significantly enhanced by 11 times, and the photoluminescence quantum yield increased from 14.8% to 46.1%. The occurrence of this phenomenon can be attributed not only to the role of Tb³⁺ as a nucleating agent in PQD glass, which facilitates the formation of more small-sized CsPbBr₃, but also to its ability to replace Pb²⁺, thereby alleviating lattice distortion and passivating defects. Moreover, the core mechanism lies in the energy transfer process between Tb³⁺ and CsPbBr₃. It has been verified that there is not only a radiative photon reabsorption process in which Tb³⁺ releases photons that are absorbed by CsPbBr₃ but also a Förster resonance energy transfer process in which Tb³⁺ directly transfers energy to CsPbBr₃ in a non-radiative form. Finally, considering the differing thermal attenuation rates of Tb³⁺ and CsPbBr₃ in glass, a temperature-dependent luminescence color-tuning strategy is proposed, which has potential application value in the field of temperature sensing.