Plasmonic metal enhanced broadband near-infrared emission from a transparent nano-glass composite containing hybrid Ag–metal/γ-Ga2O3:Ni2+ nanocrystals

Manipulating the plasmonic properties of metal nanocrystals (NCs) is key to many modern nanophotonic technologies. Here, the strategy of combining Ag+ ↔ Li+ ion exchange and controlled thermal crystallization is proposed as an effective means to prepare transparent nano-glass composites (nano-GCs) embedded with hybrid Ag–metal and γ-Ga2O3:Ni2+ NCs. Only by this method can a large amount of Ag–metal NCs (1.1 mol%) be implanted and well dispersed in the glass matrix without sacrificing their optical transmission properties. The broadband near-infrared (NIR) emission of Ni2+ is enhanced by 100% in the presence of Ag–metal NCs, which is otherwise impossible by raising the Ni2+ concentration due to the limited solubility and intrinsically weak absorption of Ni2+ in nano-GCs. The mechanisms responsible for the enhanced NIR emissions of Ni2+ are comprehensively discussed in the context of both experimental investigations and theoretical simulations. The present study not only provides a promising robust nano-GC-based gain medium for integrated optics but also offers some insights into the plasmonic metal-enhanced photoluminescence for enriched optical functions.