Experimental characterization of single-walled carbon nanotube film-Si Schottky contacts using metal-semiconductor-metal structures

We demonstrate that single-walled carbon nanotube (CNT) films make a Schottky contact on silicon by experimentally characterizing metal-semiconductor-metal (MSM) structures. We find that at temperatures above 240 K, thermionic emission is the dominant transport mechanism across CNT film-Si contacts, and at lower temperatures tunneling begins to dominate. At high bias voltages, the CNT film MSM devices exhibit a higher photocurrent-to-dark current ratio relative to that of metal control devices. Our results not only provide insight into the fundamental electronic properties of the CNT film-Si junction but also opens up the possibility of integrating CNT films as Schottky electrodes in conventional Si-based devices.