Plasmonically-Enhanced Radioluminescence Induced by Energy Transfer in Colloidal CsPbBr₃ Nanocrystals via Hybridization of Silver Nanoparticles

Nanocrystals of CsPbBr3, a colloidal perovskite, are hybridized with silver nanoparticles (Ag NPs) and organic molecules (2,5-diphenyloxazole, PPO) to improve X-ray radioluminescence (RL). It is known that charge transfer from the PPO molecules to the CsPbBr3 nanocrystals enhances the RL efficiency of the CsPbBr3 nanocrystals. In this study, Ag NPs are introduced to further enhance the RL efficiency. The plasmonic process of the Ag NPs is activated by the PPO molecules, which contain X-ray-induced high-energy charges. Subsequently, electric fields induced by the plasmonic process of the Ag NPs accelerate the charge transfer from the PPO molecules to the CsPbBr3 nanocrystals. The plasmonic effect of the Ag NPs is demonstrated by the full-width half maximum (FWHM): the photoluminescence FWHM of the hybridized CsPbBr3 nanocrystals is reduced, whereas the RL FWHM remains unchanged. The Ag-NP-induced plasmonic effect improves the RL efficiency of the PPO-decorated CsPbBr3 nanocrystals by & AP;10%. The obtained results demonstrate that a plasmonic process can strengthen the RL of X-ray scintillators for X-ray detection and imaging.