Charge dynamics in composite systems for advanced applications

Charge dynamics (i.e. the processes of chargegeneration, dissociation and collection) plays a critical role in severaladvanced applications based on composite nanosystems, including solar energy,water splitting,... [ view full abstract ]

Charge dynamics (i.e. the processes of chargegeneration, dissociation and collection) plays a critical role in severaladvanced applications based on composite nanosystems, including solar energy,water splitting, nanothermometry.

In most of them, semiconducting nanocrystalsexhibiting quantum confined effects (the so-called quantum dots, QDs) act aslight absorbing materials, which are able to generate excitons as a consequenceof photon absorption.

Managing the photogenerated charges enables theexploitation of different physico-chemical processes, including chargeseparation and collection in photoelectrochemical systems for energy conversionor tuning photoluminescence properties in luminescent nanoprobes.

Key element for driving the processes totargeted applications is the modulation of composition and size of thenanomaterials, which determines the final electronic band structure of thecomposite systems and its functional properties.

We will illustrate different examples ofcomposite systems, targeted for specific applications. (i) “Giant” compositecore-shell QDs, in which modulation of core-to-shell interface induces asingle- to double-color photoluminescence; (ii) Near-infrared QDs withincreased Stokes shift due to suitable electronic structure of the core andshell, to be applied in luminescent solar concentrators; (iii) Composite TiO2mesoporous film sensitized by “giant” QDs with high charge injection from thephotoexcited QD to the TiO2 anode, for excitonic solar cells and watersplitting.

We will discuss possible strategies to tailor
the optical features of the different systems to optimize their functional
properties, according to the specific application.