• English
  • Deutsch
  • Log In
    Password Login
    Research Outputs
    Fundings & Projects
    Researchers
    Institutes
    Statistics
Repository logo
Fraunhofer-Gesellschaft
  1. Home
  2. Fraunhofer-Gesellschaft
  3. Artikel
  4. Ballistic effects and intersubband excitations in multiple quantum well structures
 
  • Details
  • Full
Options
1998
Journal Article
Title

Ballistic effects and intersubband excitations in multiple quantum well structures

Other Title
Ballistische Effekte und Intersubband-Anregungen in Vielfachquantenfilm-Strukturen
Abstract
We have studied the transport properties of electrons in asymmetric quantum well structures upon far-infrared optical excitation of carriers from the lowest subband into the continuum. Here the photocurrent consists of a coherent component originating from ballistic transport upon excitation, and of an incoherent part associated with asymmetric diffusion and relaxation processes, which occur after the coherence has been lost. The signature of the coherent contribution is provided by a sign reversal of the photocurrent upon changing the excitation energy. This sign reversal arises from the energy-dependent interference between continuum states, which have a twofold degeneracy characterized by positive and negative momenta. The interference effect also allows us to estimate the coherent mean free path ( > 20 nm at 77 K). In specifically designed device structures, we use both the coherent and incoherent components in order to achieve a pronounced photovoltaic infrared response for detect or applications.
Author(s)
Schneider, H.
Schönbein, C.
Schwarz, Klaus  
Fraunhofer-Institut für Angewandte Festkörperphysik IAF  
Walther, Martin  
Fraunhofer-Institut für Angewandte Festkörperphysik IAF  
Journal
Physica. E  
DOI
10.1016/S1386-9477(98)00008-3
Language
English
Fraunhofer-Institut für Angewandte Festkörperphysik IAF  
Keyword(s)
  • coherent transport

  • infrared photodetector

  • Infrarot-Photodetektor

  • Intersubband-Anregung

  • intersubband excitation

  • intersubband transition

  • kohärenter Transport

  • Cookie settings
  • Imprint
  • Privacy policy
  • Api
  • Contact
© 2024