Luminescent nanomaterials

Luminescent nanomaterials are interesting for two reasons. They can display original properties specific to their size. They can also be used as building blocks for the design of complex macroscopic materials. After several decades of fundamental studies, various classes of objects have emerged. These include, for example, two-dimensional materials (atomic monosheets) and nanoparticles with single colored centers, which have only recently appeared and already offer ambitious prospects. In fact, while fundamental studies are still necessary and ongoing, these luminescent nanomaterials are now entering a second phase aimed at their use in fields as varied as information and communication technologies (nanophotonics), energy (photovoltaics and photochemicals) and health technologies. The first part of this article is devoted to a general description of luminescence processes, with a particular focus on the difference between intrinsic and extrinsic luminescence phenomena. This is followed by a description of the different classes of luminescent nanomaterials in existence. A number of these materials are then described more specifically, in particular those that have not already been the subject of articles in Techniques de l'Ingénieur. A final point in this first part is the presentation of transfer phenomena between luminescent nanomaterials, enabling systems to "talk" to each other. Finally, the most original or promising applications are presented in the second part of this article. The use of "dialogue" between luminescent nanomaterials is illustrated through photonic conversion systems for photovoltaic applications and photocatalysis. Finally, the advantages of luminescent nanomaterials for lighting (screens) or as markers/tracers and probes are presented.