Abstract
Dilute-nitride GaAsNx epilayers were grown on GaAs (001) substrates at temperatures of ∼450 °C using a radio-frequency plasma-assisted molecular/chemical beam exitaxy system. The concentration of nitrogen incorporated into the films was varied in the range between 0.01 and 0.04. High-resolution electron microscopy was used to determine the cross-sectional morphology of the epilayers, and Z-contrast imaging showed that the incorporated nitrogen was primarily interstitial. {110}-oriented microcracks, which resulted in strain relaxation, were observed in the sample with the highest N concentration ([N] ∼ 3.7%). Additionally, Z-contrast imaging indicated the formation of a thin, high-N quantum-well-like layer associated with initial ignition of the N-plasma. Significant N contamination of the GaAs barrier layers was observed in all samples, and could severely affect the carrier extraction and transport properties in future targeted devices. Dilute-nitride quantum-well-based photovoltaic solar cells were fabricated having a band-gap energy of 1.19 eV, which was attributed to the dilute-nitride layer.
Original language | English (US) |
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Article number | 011210 |
Journal | Journal of Vacuum Science and Technology B:Nanotechnology and Microelectronics |
Volume | 34 |
Issue number | 1 |
DOIs | |
State | Published - Jan 1 2016 |
ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Process Chemistry and Technology
- Electronic, Optical and Magnetic Materials
- Surfaces, Coatings and Films
- Materials Chemistry
- Instrumentation