One of the foremost challenges is to develop nanocrystal (NC) floating-gate nonvolatile memory (NVM) devices to overcome the challenge of scaling down, where NCs serve as discrete charge storage elements to make a thinner floating gate without any significant leakage with time. In recent years, significant improvements have been made in NC fabrication and in the prototypes of NC-based NVM. In this chapter, we briefly emphasize the basics of NCs and their general synthesis methods, mostly the wet-chemical method. Subsequently, we focus on those NCs that have been used for NVM devices in the recent past. We also discuss the recent efforts and research activities regarding the fabrication and characterization of NVM devices made of these NCs, which are further classified into four

categories: zero-dimensional, one-dimensional, two-dimensional, and three-dimensional.