Effects of geometry and doping on the operation of molecular transistors

The first-principles calculations of current versus gate voltage characteristics of a molecular transistor with a phenyldithiolate molecule as active element were reported. It was found that current modulation and resonant tunneling can occur at very small gate voltages when the molecule is placed in proximity to the gate electrode. It was shown that the molecular transistor can be converted from n-type to p-type by simple co-adsorption of a single oxygen atom placed near the molecule.