chapter 7 coulomb blockade and the single-electron transistorqli/ece685/ch7 _ second note.pdf ·...
TRANSCRIPT
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