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

Journal Article · Fri May 15 00:00:00 EDT 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3126711· OSTI ID:21352209

Schramm, A ^[1]; Tukiainen, A; Pessa, M ^[1]; Konetzni, C; Heyn, Ch; Hansen, W ^[2]

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1. Optoelectronics Research Centre, Tampere University of Technology, 33720 Tampere (Finland)
2. Institute of Applied Physics, University of Hamburg, D-20355 Hamburg (Germany)

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{sub n}=3x10{sup 14} cm{sup -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.

• OSTI ID: 21352209
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 10 Vol. 105; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
ARSENIC COMPOUNDS
ARSENIDES
BARYONS
CAPACITANCE
CRYSTAL DEFECTS
CRYSTAL GROWTH
CRYSTAL GROWTH METHODS
CRYSTAL STRUCTURE
DEEP LEVEL TRANSIENT SPECTROSCOPY
ELECTRIC POTENTIAL
ELECTRICAL PROPERTIES
ELECTRON EMISSION
ELECTRONS
ELEMENTARY PARTICLES
EMISSION
EPITAXY
FERMIONS
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
HADRONS
INDIUM ARSENIDES
INDIUM COMPOUNDS
LEPTONS
LUMINESCENCE
MATERIALS
MOLECULAR BEAM EPITAXY
NANOSTRUCTURES
NEUTRONS
NUCLEONS
OPTICAL PROPERTIES
PHOTOLUMINESCENCE
PHOTON EMISSION
PHYSICAL PROPERTIES
PNICTIDES
QUANTUM DOTS
RECOMBINATION
RELAXATION
SATURATION
SCHOTTKY BARRIER DIODES
SEMICONDUCTOR DEVICES
SEMICONDUCTOR DIODES
SEMICONDUCTOR MATERIALS
SPECTROSCOPY