Drastic reduction of shot noise in semiconductor superlattices
1Department of Physics and Astronomy, State University of New York at Stony Brook, Stony Brook, New York 11794-3800, USA.
Abstract:
We have found experimentally that the shot noise of the tunneling current I through an undoped semiconductor superlattice is reduced with respect to the Poissonian noise value 2eI, and that the noise approaches 1/3 of that value in superlattices whose quantum wells are strongly coupled. On the other hand, when the coupling is weak or when a strong electric field is applied to the superlattice, the noise becomes Poissonian. Although our results are qualitatively consistent with existing theories for one-dimensional multibarrier structures, the theories cannot account for the dependence of the noise on superlattice parameters that we have observed.
Related Concept Videos
01:24Metal-Semiconductor Junctions
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The semiconductor's...
01:12Fermi Level Dynamics
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
01:27Biasing of Metal-Semiconductor Junctions
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...