To change transport gap of semiconducting nanoparticles without disturbing the optical one: Core-shell approach

We show that transport gap of semiconducting nanoparticles can be changed without disturbing the optical gap. This is achieved through inorganic-organic hybrid core-shell approach. Different inorganic nanoparticles with a bandgap in the UV to NIR range are used as the core; as a shell to the nanoparticles, a monolayer of different organic molecules is used. With the inclusion of the shell layer, optical gap of the nanoparticles does not change. Transport gap, as obtained from current-voltage characteristics of a single nanoparticle with scanning tunneling microscope tip, changes to that of the shell-material irrespective of the bandgap of core nanoparticles.