Atomic scale high-angle annular dark field STEM analysis of the N configuration in dilute nitrides of GaAs

Herrera, M.; Ramasse, Quentin M.; Morgan, Dan; González, David; Pizarro, J.; Yáñez, Andrés Suárez; Galindo, Pedro L.; Garcı́a, R.; Du, Mao‐Hua; Zhang, Shou-Cheng; Hopkinson, M.; Browning, Nigel D.

doi:10.1103/physrevb.80.125211

Cited by 24 publications

(17 citation statements)

References 57 publications

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“…However, the existence of strain in the films and relaxation of strain at the surfaces of the TEM specimen make interpretation of the measured intensity profile less straightforward. For example, atomic size mismatch strain induced reversed ADF-STEM image contrast between dilute semiconductor heteroepitaxial strained layers and substrates has been reported in GaNAs/GaAs [8,11,12] and SiC/Si systems [9]. In addition, a reduction in the ADF image intensity of InGaAs layers at both interfaces with adjacent GaAs layers due to strain relaxation has also been observed [10].…”

Section: Introductionmentioning

confidence: 92%

Effects of small specimen tilt and probe convergence angle on ADF-STEM image contrast of Si0.8Ge0.2 epitaxial strained layers on (100) Si

Robertson

Kawasaki

et al. 2012

Ultramicroscopy

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The effects of specimen tilt and probe convergence angle on annular dark field (ADF) image contrast of Si 0.8 Ge 0.2 heteroepitaxial strained layers on (100) Si were investigated in a 200 kV scanning transmission electron microscope (STEM) for a TEM specimen thickness of 195 nm. With 0.5 degrees of specimen tilt away from the exact /011S zone-axis orientation, the signal-to-noise level of atomic columns was significantly reduced for both Si 0.8 Ge 0.2 and Si in high resolution ADF-STEM lattice images. When the specimen was tilted 0.5 degrees around the /011S axis, or the STEM probe convergence semiangle was reduced from 14.3 to 3.6 mrad, the ADF-STEM image intensity profiles across the Si 0.8 Ge 0.2 and Si layers changed significantly as compared to those obtained at the exact /011S zone axis orientation, and no longer reflected the composition changes occurring across the layer structure. Multislice image simulation results revealed that the misfit strain between the Si 0.8 Ge 0.2 and Si layers, and strain relaxation near the surface of the TEM specimen, were responsible for the observed changes in image intensity.Crown

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Section: Introductionmentioning

confidence: 92%

Effects of small specimen tilt and probe convergence angle on ADF-STEM image contrast of Si0.8Ge0.2 epitaxial strained layers on (100) Si

Robertson

Kawasaki

et al. 2012

Ultramicroscopy

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“…Experimental intensity ratio or contrast is then compared with a simulated ratio instead of direct intensity comparison. The ratio has a low dependency on for instance thickness, which is otherwise a critical parameter in quantitative HAADF-STEM work (Grillo et al, 2008;Herrera et al, 2009;Rosenauer et al, 2009). The method has been successfully applied to composition analysis of various structures, quantum wells being the most typical object (Grillo et al, 2008;Herrera et al, 2009;Grillo, 2009;Rosenauer et al, 2011).…”

Section: Introductionmentioning

confidence: 94%

Compositional characterization of GaAs/GaAsSb nanowires by quantitative HAADF-STEM

Kauko

Grieb

Bjørge

et al. 2013

Micron

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“…In ADF images, the GaAsSbN layers appear brighter than the GaAs, mainly due to the N presence [37]. No clear contrasts due to, for example, composition modulation or vertical segregation phenomena were exhibited in samples along the growth direction as we can see in Fig.…”

Section: Resultsmentioning

confidence: 99%

Sb and N Incorporation Interplay in GaAsSbN/GaAs Epilayers near Lattice-Matching Condition for 1.0–1.16-eV Photonic Applications

et al. 2017

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As promising candidates for solar cell and photodetection applications in the range 1.0–1.16 eV, the growth of dilute nitride GaAsSbN alloys lattice matched to GaAs is studied. With this aim, we have taken advantage of the temperature gradient in the molecular beam epitaxy reactor to analyse the impact of temperature on the incorporation of Sb and N species according to the wafer radial composition gradients. The results from the combination of X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopies (EDS) show an opposite rate of incorporation between N and Sb as we move away from the centre of the wafer. A competitive behaviour between Sb and N in order to occupy the group-V position is observed that depends on the growth rate and the substrate temperature. The optical properties obtained by photoluminescence are discussed in the frame of the double-band anticrossing model. The growth conditions define two sets of different parameters for the energy level and the coupling interaction potential of N, which must be taken into account in the search for the optimum compositions 1–1.15-eV photonic applications.

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Atomic scale high-angle annular dark field STEM analysis of the N configuration in dilute nitrides of GaAs

Cited by 24 publications

References 57 publications

Effects of small specimen tilt and probe convergence angle on ADF-STEM image contrast of Si0.8Ge0.2 epitaxial strained layers on (100) Si

Effects of small specimen tilt and probe convergence angle on ADF-STEM image contrast of Si0.8Ge0.2 epitaxial strained layers on (100) Si

Compositional characterization of GaAs/GaAsSb nanowires by quantitative HAADF-STEM

Sb and N Incorporation Interplay in GaAsSbN/GaAs Epilayers near Lattice-Matching Condition for 1.0–1.16-eV Photonic Applications

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