The size of QDs is crucial because it directly affects their quantum confinement effects. Smaller QDs have a higher degree of quantum confinement, leading to changes in their electronic and optical properties. For instance, smaller QDs will emit light at shorter wavelengths (towards the blue end of the spectrum), while larger QDs will emit light at longer wavelengths (towards the red end of the spectrum). This size-dependent emission property is known as quantum size effect.
