Optical density of states in ultradilute GaAsN alloy: Coexistence of free excitons and impurity band of localized and delocalized states

Journal Article · Mon Jul 14 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4886178· OSTI ID:22308706

Bhuyan, Sumi; Pal, Bipul; Bansal, Bhavtosh ^[1]; Das, Sanat K.; Dhar, Sunanda ^[2]

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1. Indian Institute of Science Education and Research Kolkata, Mohanpur Campus, Nadia 741252, West Bengal (India)
2. Department of Electronic Science, University of Calcutta, 92 A.P.C. Road, Kolkata 700009 (India)

Optically active states in liquid phase epitaxy-grown ultra-dilute GaAsN are studied. The feature-rich low temperature photoluminescence spectrum has contributions from excitonic band states of the GaAsN alloy, and two types of defect states—localized and extended. The degree of delocalization for extended states both within the conduction and defect bands, characterized by the electron temperature, is found to be similar. The degree of localization in the defect band is analyzed by the strength of the phonon replicas. Stronger emission from these localized states is attributed to their giant oscillator strength.

• OSTI ID: 22308706
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 2; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ARSENIC COMPOUNDS
CRYSTAL DEFECTS
ELECTRON TEMPERATURE
ELECTRONIC STRUCTURE
EXCITONS
GALLIUM COMPOUNDS
IMPURITIES
LIQUID PHASE EPITAXY
NITROGEN COMPOUNDS
OPACITY
OSCILLATOR STRENGTHS
PHONONS
PHOTOLUMINESCENCE
SPECTRA
TERNARY ALLOY SYSTEMS