Chapter 7 Coulomb Blockade and the Single-electron Transistor Lecture given by Qiliang Li

7.2 Single-Electron Transistor Adding gate control on a Coulomb-Blockade structure – single-electron tunneling transistor or simply single-electron transistor (SET) Vg > 0 will depress the Fermi level, Ef Vg < 0 will raise Ef Above, below and lie up with Ef of right/left side

The net charge on the island:

Solved:

An electron tunnel into the island from b, the change of stored energy is

Similarly for an electron from island to Junction a:

Assume initially island is charge neutral (n=0), an electron tunnels into the island through junction b

Now the island is has one electron (n=1), the electron tunnels off from the island into junction a:

To observe a current from junction b to a, both condition need to be met: Current > 0

Coulomb diamonds Charge stability diagram Shaded regions: no tunneling is allowed

SET has potential for high-speed, high-density and low-power dissipation.

7.3 Other SET and FET structures Carbon nanotube FET

InP nanowire FET for single electron tunneling

Benzene Molecule as a resonant tunneling transistor

Molecular SET