Photoassisted transport in silicon dangling bond wires

摘要

We theoretically investigate charge transport through dangling bond (DB) nanostructures built on a passivated silicon (100) surface by selectively removing hydrogen atoms. We focus on dangling bond wires and on T-junctions. In the latter case, destructive quantum interference effects lead to a strong suppression of charge transport mediated by the DB electronic states. We demonstrate, however, that by applying a time periodic voltage, mimicking irradiation with monochromatic light, a dramatic enhancement of the current up to the μA range can be achieved. This result is however limited by the restriction on the AC field strength and frequency that bulk states should minimally contribute to charge transport; otherwise current leakage will set in. Despite this constraint, transconductance values of the order of 10~(-6) A/V can be achieved, illustrating the potential of the discussed systems to find applications in nanoscale electronics.