What is the barrier for tunneling through alkyl monolayers? Results from n- And p-Si-Alkyl/Hg junctions

The electronic transport through alkyl chains of a molecular level was compared and analyzed through C-Si bonds, and contacted by charge transfer between the molecule and the electrode as a result of this bond formation. A semiconductor/saturated molecule-metal junction, two transport barriers can exist simultaneously, a Schottky barrier inside the semiconductor. The tunnel barrier is affected by the molecular length or molecular layer width, and by the molecular levels closest to the Fermi level and band edges of each electrode. The existence of two distinct barriers in a system allows to extract complementary information about the molecular junction. Changing the doping type of the electrode can effect both the Schottky barrier and the tunnel barrier. For p-Si molecular junctions in both reverse-and forward-bias directions, the current is dominated by majority carriers, that is, holes, which flow from the Si to the Hg in forward bias and from the Hg to the Si in reverse bias.