NIR-II silver-based quantum dots: Synthesis and applications

Silver-based quantum dots (QDs) such as Ag₂S, Ag₂Se, and Ag₂Te, which emit in the second near-infrared window (NIR-II, 900–1700 nm), have attracted great research interest due to their prominent optical properties and eco-friendly compositions. Over the past decade, the controllable synthesis, bandgap modulation, and fluorescence improvement of NIR-II Ag-based QDs have greatly promoted their practical applications. In this review, we summarize the development process and latest achievements of NIR-II Ag-based QDs, covering major synthesis techniques for fabricating NIR-II Ag-based QDs, general methods for improving their fluorescence properties and recent advances in the applications of NIR-II Ag-based QDs from bioimaging to optoelectronic devices. Finally, we discuss the challenges and prospects of NIR-II Ag-based QDs in their optical properties and applications. This review aims to present synthesis and modification strategies and future application prospects for NIR-II Ag-based QDs, providing guidance for the design and integration of fluorescent probes in NIR-II window.