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Schlagwörter:
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Zusammenfassung:
Here, the surface functionalization of CdSe and CdSe/CdS core/shell
nanocrystals (NCs) with compact chloride and indium-chloride-complex
ligands is reported. The ligands provide not only short interparticle
distances but additionally control doping and passivation of surface
trap states, leading to enhanced electronic coupling in NC-based arrays.
The solids based on these NCs show an excellent electronic transport
behavior after heat treatment at the relatively low temperature of 190
degrees C. Indeed, the indium-chlorido-capped 4.5 nm CdSe NC based
thin-film field-effect transistor reaches a saturation mobility of = 4.1
cm(2) (V s)(-1) accompanied by a low hysteresis, while retaining the
typical features of strongly quantum confined semiconductor NCs. The
capping with chloride ions preserves the high photoluminescence quantum
yield (approximate to 66%) of CdSe/CdS core/shell NCs even when the CdS
shell is relatively thin (six monolayers). The simplicity of the
chemical incorporation of chlorine and indium species via solution
ligand exchange, the efficient electronic passivation of the NC surface,
as well as their high stability as dispersions make these materials
especially attractive for wide-area solution-processable fabrication of
NC-based devices.
