Neutron-irradiated Schottky diodes with self-assembled InAs quantum dots: Optical and electrical properties

Link:
Autor/in:
Erscheinungsjahr:
2009
Medientyp:
Text
Schlagworte:
  • Temperature sensors
  • Silicon carbide
  • Schottky barrier diodes
  • Semiconductor Quantum Dots
  • Semiconductor Quantum Wells
  • Gallium Arsenide
  • Temperature sensors
  • Silicon carbide
  • Schottky barrier diodes
  • Semiconductor Quantum Dots
  • Semiconductor Quantum Wells
  • Gallium Arsenide
Beschreibung:
  • The effect of neutron irradiation on optical and electrical properties of self-assembled InAs/GaAs quantum dots (QDs) is studied for neutron doses up to phi(n)=3x10(14) cm(-2). The QDs are embedded in n-type GaAs Schottky diodes grown by molecular beam epitaxy on GaAs(001). We observe an initial increase in QD photoluminescence followed by a decrease as a function of neutron irradiation. The increase in photoluminescence is attributed to a more effective carrier trapping and relaxation from the wetting layer into the QDs via radiation-induced defects. The losses of photoluminescence at higher neutron doses are caused by defects, which act as nonradiative recombination centers. The observed dependence of the photoluminescence on the laser excitation power can be explained with saturation effects. Deep level transient spectroscopy experiments reveal multiple overlapping electron traps. Furthermore, an enhanced introduction of defects in the QD layer is observed. Electrical characterization of the Schottky diodes via capacitance-voltage spectroscopy reveals that the doping condition in the diodes changes due to the introduction of defects. This fact has to be taken into account if QDs are used in electrical devices in radiation-harsh environments as it is shown by low-temperature deep level transient spectroscopy experiments on electron emission processes from QD levels.
Lizenz:
  • info:eu-repo/semantics/restrictedAccess
Quellsystem:
Forschungsinformationssystem der UHH

Interne Metadaten
Quelldatensatz
oai:www.edit.fis.uni-hamburg.de:publications/b0417ea4-9db9-4e21-b1de-f3ca36f59efd