| 1. |
- Duteil, F., et al.
(author)
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Er/O doped Si1-xGex alloy layers grown by MBE
- 2001
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In: Optical materials (Amsterdam). - 0925-3467 .- 1873-1252. ; 17:1-2, s. 131-134
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Conference paper (other academic/artistic)abstract
- Silicon-based light emitting diodes (LEDs) containing an Er/O-doped Si1-xGex active layer have been studied. The structures were grown by molecular beam epitaxy (MBE), with Er and O concentrations of 5 × 1019 and 1 × 1020 cm-3, respectively, using Er and silicon monoxide sources. The microstructure has been studied by X-ray diffraction (XRD) and cross-sectional transmission electron microscopy, and it is found that Er/O-doped Si0.92Ge0.08 layers of high crystalline quality, can be obtained. Electroluminescence (EL) measurements have been performed on reverse-biased Er/O doped diodes both from the surface and from the edge and the emission at 1.54 µm associated with the Er3+ ions has been studied at 300 K and lower temperatures. To evaluate the possibility to use a Si1-xGex layer for waveguiding in Si-based optoelectronics, studies of the refractive index n of strained Si1-xGex as a function of the Ge concentration have been done by spectroscopic ellipsometry in the range 0.3-1.7 µm. At 1.54 µm the refractive index increases monotonically with the Ge concentration up to n = 3.542 for a Ge concentration of 21.3%. © 2001 Elsevier Science B.V.
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| 2. |
- Henning, P, et al.
(author)
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Compositional information from amorphous Si-Ge multilayers using high-resolution electron microscopy imaging and direct digital recording
- 1996
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In: Ultramicroscopy. - 0304-3991. ; 66:3-4, s. 221-235
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Journal article (peer-reviewed)abstract
- A simple method for extracting compositional information from high-resolution electron microscopy images of an amorphous two-element system using a slow-scan CCD camera has been developed. The method has been evaluated on amorphous Si/Ge multilayers. The characterisation of the multilayers provided information about thickness of the layers, maximum concentrations within the layers and elemental profiles across the boundaries. It was shown that the intensity profiles could be corrected for the wedge shape of the specimen and that the derived compositional profile was independent of average sample thickness variation within the range of the cross-section sample thickness.The results have been compared to analysis performed by Auger electron spectroscopy depth profiling on as-prepared multilayers as well as by energy-dispersive X-ray analysis and electron energy filtered images of cross-sections. The proposed HREM image contrast evaluation method gave spatial resolution in chemical analysis across the thin layers comparable in accuracy to the other methods, whereas the oscillation amplitude for the concentration is slightly less due to specimen preparation artifacts.
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| 3. |
- Hultaker, A., et al.
(author)
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Electrical and optical properties of sputter deposited tin doped indium oxide thin films with silver additive
- 2001
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In: Thin Solid Films. - 0040-6090 .- 1879-2731. ; 392:2, s. 305-310
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Conference paper (other academic/artistic)abstract
- Tin doped indium oxide (ITO) films with a few mol% of silver were prepared by reactive DC magnetron sputtering. The purpose of adding silver is to boost conductivity. The real part of the refractive index of ITO was determined from ellipsometry data, applying a model combining a Drude and a Lorentz term. The imaginary part was calculated from the absorptance, which was derived from transmittance and reflectance data. We found that up to 6 mol% of silver additive enhanced the conductivity by as much as a factor of two for layers post-treated at 200 and 300°C in reducing gas consisting of 93% N2 and 7% H2. For samples with 1 mol% silver, which was post-treated at 100 and 200°C, we observed an increase in the luminous transmittance. The transmittance decreased with increased silver content. © 2001 Elsevier Science B.V.
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| 4. |
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| 5. |
- IVANOV, I, et al.
(author)
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GROWTH OF EPITAXIAL ALN(0001) ON SI(111) BY REACTIVE MAGNETRON SPUTTER-DEPOSITION
- 1995
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In: JOURNAL OF APPLIED PHYSICS. - : AMER INST PHYSICS. - 0021-8979. ; 78:9, s. 5721-5726
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Journal article (other academic/artistic)abstract
- 2H-AlN(0001) layers have been grown on Si(lll) by reactive magnetron sputtering from an Al target in Ar+N-2 gas mixtures at temperatures T-s=400-900 degrees C. Variations in reactive gas consumption, target voltage, and current-voltage characteristics ver
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