• Cobalt
• Copper
• ITO
• Magneto-optical
• Nanoparticles

: Nanomaterials have captured the attention of the scientific community for their peculiar optical and structural properties, which emerge when the dimensions are reduced to a nanometric scale. A particularly interesting optical phenomenon associated with metallic nanoparticles is the Localized Surface Plasmon Resonance (LSPR), resulting from the fact that the conduction electrons on the surface of the nanoparticles collectively oscillate in response to the interaction with a light radiation. The plasmon resonance frequency and the intensity of the LSPR signal depend on various factors, including size, shape and material of the nanoparticles, but also on the surrounding environment. Recently, alternative materials to noble metals for plasmonics have emerged, such as doped semiconductors. In these, doping, i.e. the introduction of impurities or elements foreign to the semiconductor structure, allows to modify the electron density and, consequently, to control the LSPR.
In this paper, the main effects of doping on the plasmon resonance frequency and their applications will be reviewed, with particular attention to tin-doped indium oxide (ITO) nanoparticles and their near-infrared (NIR) response, also exploring the potential of magnetic cations doping.