Exchanges

Exchanges

Scientific Exchanges form an integral part of the NanoTP network. They can be of different duration, up to a maximum of 3 months (6 months for early stage researchers in exceptional circumstances). Funding covers travel and subsistence.

For more details of the procedure for applying for exchange funding, please log into the website via the link top-right on this page. To register with the NanoTP project, please contact us

Core-shell doping of nanocrystals

A barrier to the widespread utilization of nanocrystal (NC) devices lies on the relatively poor electrical performance of nanoparticulate solids. The main challenges are to achieve effective doping and strong electronic connectivity across NCs. Dopant segregation, quantum confinement and incomplete screening are usually held responsible for difficulties in dopant introduction and activation. Routes to overcome these problems may involve shaping the chemistry of the NC surface to introduce a chemical barrier for dopant out-diffusion, or to modify the screening properties of the NCs to tune electrical levels. For instance, Ge has a lower valence band than Si, so that donors in a Si-NC core with a Ge shell should dump their electrons to the Ge-rich surface. This involves core-shell structuring of NCs. Although many of the results are yet to be obtained, important milestones were already attained during the visit (see below). With the established collaboration, we will investigate the electronic doping of group-IV and II-VI nanocrystals by means of density functional calculations. Core and shell atoms of the NCs will be replaced in NCs made of thousands of atoms and with sizes that span the values in real experiments. Most of the analisys will be carried out by calculating the local density of states, as well as ionization energies and electron affinities of doped NCs. [More]

1 October 2013