Resonant tunneling through donor impurities in double-barrier structures. / Tunelamento ressonante através de impurezas doadoras em estruturas de dupla barreira.

AUTOR(ES)
DATA DE PUBLICAÇÃO

1994

RESUMO

We have investigated resonant tunneling in GaAs/(AlGa)As double barrier structures which have been fabricated into square mesoscopic and macroscopic size mesas (∼ 10μm × 10μm) A δ layer with different concentrations of Silicon donors was incorporated at the centre of the quantum well. The I(V) characteristics show some features below the threshold for the main resonance that are due to impurity related state. Such localized states are found to be related to the presence of donor impurities in the vicinity of the quantum well with binding energies much higher than the single isolated hydrogen donor. These higher binding energy states are identified as being due to random pairs of shallow donors. In some devices where an isolated impurity related state can be identified in the 1(V characteristics a remarkable effect is observed. A peak appears at low temperatures (below 1K) in the 1(V) characteristics when the emitter Fermi level matches the localized state. Such feature is attributed to the Coulomb interaction between the electron on the localized site and the electrons in the Fermi sea of the 2DEG.

ASSUNTO(S)

resonant tunneling semicondutores propriedades elétricas semiconductors singularidade do nível de fermi fermi edge singularity electrical properties tunelamento ressonante

ACESSO AO ARTIGO

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