Degenerately doped semiconductor nanocrystals (NCs) and in particular, doped metal oxide NCs have emerged as an important class of materials in the last decade for their ability to sustain localized surface plasmon resonance (LSPR) in the mid-to near-infrared region of the electromagnetic spectrum. LSPR, which arises due to the resonant oscillations of carriers with electromagnetic radiation, has predominantly been studied in noble metals such as Au and Ag. Already in that context, LSPR has found a variety of applications such as photothermal therapy, photovoltaics, electrochromic windows, sensing and surface-enhanced infrared absorption spectroscopy. Unlike noble metals whose LSPR remains restricted to a narrow window in the visible region, doped metal oxide NCs offer an advantage in that their LSPR that can be tuned across a wide spectral range in the infrared region. While in noble metals, infrared resonance requires large sizes or highly anisotropic shapes, in doped semiconductors this tunability can also be achieved by merely altering the free carrier density in the NCs (see equation 1).