Abstract of the project

Transition metal dichalcogenides (TMDs) offer a huge flexibility in tuning electronic properties. Their electronic structure is found to change dramatically from bulk to few monolayer samples. Moreover, some TMDs exhibit remarkable bulk thermoelectric behavior. According to theoretical predictions, these may be further improved in few monolayer thick nanostructures thanks to changes in the electronic structure. On the other hand, thermoelectric performance could be also improved by suppressing the thermal conductivity via engineering of the microstructure. Indeed, TMD flakes can be produced by liquid phase exfoliation of their bulk counterpart using scalable and cheap methods. Restacked nano-flake assemblies offer an ideal nanostructured morphology that effectively scatters phonon of different wavelengths, thus suppressing the lattice thermal conductivity, whose value in single flakes is typically in the range of tens Wm^-1K^-1 at room temperature. The aim of our proposal is to explore the potential of these features – i.e. electronic confinement and nanostructured morphology – in TMD samples of different forms (large flakes, epitaxial ultrathin films, heterostructures and nanoflake assembiles), in view of enhancing the thermoelectric performance of these systems for applications in energy conversion or cooling.