Quantized aggregation phenomena in II‐VI‐semiconductor colloids

摘要: Highly concentrated 0.5 M II-VI semiconductor quantum dot solutions for coating applications can be synthesized employing chalcogenolysis and condensation of functionalized cluster-like cadmium zinc ethoxyacetates. Furthermore, in nucleation studies on CdSe solutions, new magic clusters between 0.42 1.7 nm size were found exhibiting sharp HOMO-LUMO resonances (lowest absorption features) the optical spectra. High resolution small angle X-ray scattering (SAXS) measurements performed 3.4 corroborate size. Information intra-cluster structure was hard to derive with respect cluster These species could Koch pyramids a fractal dimension D f =2 as well non-fractal zincblende (additionally checked by XRD HRTEM). In any case rather chain-like (D = 1 ) aggregates are formed. It further will shown that alcoholic sols initially nucleated seeds highly reactive. Their transitions strongly modified externally induced chemical reactions. For example, aminosilane capped decompose rapidly upon exposure phosphines. After period few hours, they begin re-grow their original or reorganize give smaller 0.85 subunits depending P/N ratio. contrast, phosphine-capped double if exposed amines. The last process libcrates ions into solution complementary polarographic measurements.