(a) Illustration of the synthesis method to prepare CdS QDs, (b) TEM images of the CdS QDs, (c)–(e) HRTEM images of the CdS QDs, FFT pattern (inset) of single CdS QDs, (f) diameters distribution of the CdS QDs, (g) and (j) the SEM images of CdS QDs, (h) AFM image of the CdS QDs, four QDs are labelled as A, B, C, and D, (i) size measurement of the four QDs in panel (h).