Nanoparticles possess several advantages over 1D and 2D structures. For instance, in nanoparticles the carrier travelling distance is short and the carrier lifetime is long. However, connecting electrodes to a single nanoparticle is not a trivial task, which presents an obstacle to progress in areas such as electronics and optoelectronics. Devices containing randomly spread particles atop closely spaced leads made by break junction or tilt-angle evaporation techniques have been demonstrated, but developers would prefer a more routine approach.
Recently, researchers from the Institute of Physics, Academia Sinica, in Taiwan, have proposed and demonstrated a reliable approach for producing nanoparticle devices. The circuits fabricated by the team contain a single ZnO particle embedded in a nanopore structure and exhibit photovoltaic functionality with a fill factor of 48%.
Suits most materials
What’s more, the method provides a route for making electronic devices containing a single nanoparticle of virtually any material. Based on the device fabrication process, the team is now developing a technique that allows the chemical potential of an embedded nanoparticle to be tuned by a surrounding gate electrode. In this way, field-effect transistors containing a single semiconductor nanoparticle could be reproducibly constructed.
In a related project, the scientists have also used the manipulation probes to pick up selected objects such as nanowires, nanotubes and graphene sheets and place them on top of pre-prepared electrodes crossing the holes on a chip. This would allow for correlated structural TEM inspection and rigorous electrical characterization on the same specimen.
Nanotechnology 23 (2012) 165201 (6pp).