Optical transitions in GaNAs quantum wells with variable nitrogen content embedded in AlGaAs

Journal Article · Wed Jun 15 00:00:00 EDT 2016 · AIP Advances

DOI:https://doi.org/10.1063/1.4953894· OSTI ID:22611548

Noda, T. ^[1]; Mano, T.; Sakuma, Y. ^[2]

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1. Photovoltaic Materials Unit, National Institute for Materials Science, 305-0047 Tsukuba (Japan)
2. Photonic Materials Unit, National Institute for Materials Science, 305-0047 Tsukuba (Japan)

We investigate the optical transitions of GaN{sub x}As{sub 1−x} quantum wells (QWs) embedded in wider band gap AlGaAs. A combination of absorption and emission spectroscopic techniques is employed to systematically investigate the properties of GaNAs QWs with N concentrations ranging from 0 – 3%. From measurement of the photocurrent spectra, we find that besides QW ground state and first excited transition, distinct increases in photocurrent generation are observed. Their origin can be explained by N-induced modifications in the density of states at higher energies above the QW ground state. Photoluminescence experiments reveal that peak position dependence with temperature changes with N concentration. The characteristic S-shaped dependence for low N concentrations of 0.5% changes with increasing N concentration where the low temperature red-shift of the S-shape gradually disappears. This change indicates a gradual transition from impurity picture, where localized N induced energy states are present, to alloying picture, where an impurity-band is formed. In the highest-N sample, photoluminescence emission shows remarkable temperature stability. This phenomenon is explained by the interplay of N-induced energy states and QW confined states.

• OSTI ID: 22611548
• Journal Information: AIP Advances, Vol. 6, Issue 6; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 2158-3226
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION SPECTROSCOPY
ALUMINIUM ARSENIDES
CONCENTRATION RATIO
DENSITY OF STATES
ELECTRONIC STRUCTURE
GALLIUM ARSENIDES
GALLIUM NITRIDES
GROUND STATES
IMPURITIES
MODIFICATIONS
NITROGEN ADDITIONS
PHOTOCURRENTS
PHOTOLUMINESCENCE
QUANTUM WELLS
RED SHIFT
SPACE DEPENDENCE
SPECTRA
STABILITY
TERNARY ALLOY SYSTEMS
X-RAY SPECTROSCOPY