Gd3 + -mediated crystallization homogenization in perovskite glass for high-performance x-ray scintillators and white LEDs

Abstract

Metal halide perovskite nanocrystals in glass suffer from random crystallization, causing spatial and size inhomogeneity that limits performance. This study uses Gd3+ as a network modifier to disrupt the [SiO4]/[BO4] network, increasing non-bridging oxygen and reducing melt viscosity. This process suppresses random nucleation and leads to crystallization behavior that can be reasonably attributed to an Ostwald-ripening process, yielding highly uniform CsPbI3 nanocrystals, high crystallinity, and minimal defects. Structural homogenization brings notable optical improvements: the optimized CsPbI3:1Gd sample shows a threefold increase in photoluminescence quantum yield and prolonged fluorescence lifetime. As an x-ray scintillator, Gd incorporation raises glass density and effective atomic number, enabling excellent x-ray attenuation. The composite achieves a high spatial resolution of 14.6 lp/mm, a low detection limit of 1.59 mGy/s, and outstanding irradiation stability (maintaining 86% light yield of Bi4Ge3O12 crystals). In white light-emitting diodes, it delivers a high color rendering index (Ra = 87.2), a luminous efficacy of 77.9 lm/W, and 116% National Television System Committee color gamut, with stable performance under driving currents of 25–200 mA, demonstrating great potential for solid-state lighting and displays.