Charge interaction with quantum dots

Nano-confinement of metal and semi-conductor materials can lead to marked changes in their electronic behaviour. Their unique properties resulted in an increased interest in using these nanoparticles (NPs) in materials science. Furthermore, with the discovery of the symbiotic nature of metal/semi-conductor heterostructures, the use of NPs in applications such as photocatalysis and opto-electric devices, like photovoltaic cells, has increased. The exceptional properties of carbon nanotubes (CNTs), as well as their unique structure, have led to increased investigation into their behavior in such hetero-structured complexes. Large surface-to-volume ratios, chemical inertness, and lack of porosity make CNTs prime candidates as catalyst supports. In more complex systems, the electrical properties of the CNTs increase the yield of catalyzed reactions due to the electronic interactions of certain NPs and CNTs. Based on the fact that charge transfer between quantum dots and CNTs has been reported, certain semi-conducting NPs have been covalently linked to CNTs to make hetero-junction electronic devices. ... 

The photoluminescence quenching of semiconductor CdSe/ZnS quantum dots (QDs) caused by suifacely attached porphyrins increases with QDs size decrease. Porphyrin-QD interaction induces a pertubation of the excitonic wave function leading to a net charge localisation of the electron-hole pair accompanied by an increase of radiationless decay rates being proportional to the calculated radial probability of the confined exciton wave function at QD surface. 

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