Charge transport in printed silicon nanoparticle networks

Includes abstract.Includes bibliographical references.For the first time, the charge transport mechanisms in printed silicon nanoparticle networks have been comprehensively studied using variable temperature IV characteristics and Hall effect measurements, supported by microscopy studies. The conductivity can be described as hopping percolation in which activated charge transport is limited by band bending at the interface between particles and electron trapping at surface states. To probe the charge transport, two types of printed silicon nanoparticle networks based on milled silicon nanoparticles and highly doped p-type chemical vapour synthesised nanoparticles, were studied and compared

A novel mode of current switching dependent on activated charge transport

We demonstrate a fully printed transistor with a planar triode geometry, using nanoparticulate silicon as the semiconductor material, which has a unique mode of operation as an electrically controlled two-way (double throw) switch. A signal applied to the base changes the direction of the current from between the collector and base to between the base and emitter. We further show that the switching characteristic results from the activated charge transport in the semiconductor material, and that it is independent of the dominant carrier type in the semiconductor and the nature of the junction between the semiconductor and the three contacts. The same equivalent circuit, and hence similar device characteristics, can be produced using any other material combination with non-linear current-voltage characteristics, such as a suitable combination of semiconducting and conducting materials, such that a Schottky junction is present at all three contacts