As is very well known and discussed in this book, semiconductors show dramatic quantization effects when charge carriers (electrons and holes) are confined by potential barriers to small regions of space where the dimensions of the confinement are less than the deBroglie wavelength of the charge carriers, or equivalently, the nanocrystal (NC) diameter is less than twice the Bohr radius of excitons in the bulk material. The length scale at which these effects begin to occur in semiconductors is less than approximately 25–10 nm depending on effective mass.