Influence of growth conditions on the photoluminescence of pseudomorphic MBE grown Si1-xGex quantum wells

Brunner, J.; Menczigar, U.; Gail, M.; Friess, E.; Abstreiter, G.

doi:10.1016/0022-0248(93)90657-i

Cited by 10 publications

(4 citation statements)

References 12 publications

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“…The consequence here is the enhancement of the PL intensity of sample C compared with sample B due to a stronger carrier confinement. Meanwhile, the PL intensities of samples D and E are weaker than that of sample C, although the experimentally and theoretically predicted band offsets at the conduction and valence band edges are larger than those of sample C. From the discussion in figure 2, this result could be attributed to the influence of point defects in the Ge 1−x Sn x layer, meaning that these defects act as non-radiative recombination centers by reducing the PL intensity [22]. Considering these results, not only large energy band offsets but also high crystallinity in double heterostructures are essential to enhance the efficiency of PL emission.…”

Section: Resultsmentioning

confidence: 87%

Optoelectronic properties of high-Si-content-Ge_1−x–ySi_xSn _y /Ge_1−xSn_x/Ge_1−x–ySi_xSn_y double heterostructure

Fukuda¹,

Rainko²,

Sakashita³

et al. 2018

Semicond. Sci. Technol.

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The optoelectronic properties of Ge 1−x−y Si x Sn y /Ge 1−x Sn x /Ge 1−x−y Si x Sn y double heterostructures pseudomorphically grown on a Ge substrate were investigated. The photoluminescence (PL) intensity of the sample with Ge 0.66 Si 0.23 Sn 0.11 cladding layers is three times larger compared to PL from structure with a Ge cladding layer, which can be attributed to higher energy band offsets at both conduction and valence band edges at the Ge 0.91 Sn 0.09 /Ge 0.66 Si 0.23 Sn 0.11 interface. The PL spectrum of the sample with the Ge 0.66 Si 0.23 Sn 0.11 cladding layer at room temperature can be deconvoluted into four components, and the origins of these components can be assigned to direct and indirect transitions by measuring the temperature dependence of each component's intensity. In addition, we examined the formation and characterization of strain-relaxed Ge 1−x−y Si x Sn y /Ge 1−x Sn x /Ge 1−x−y Si x Sn y double heterostructures to relieve the compressive strain in the Ge 1−x Sn x layer. Stacking faults were observed in the Ge 1−x Sn x and Ge 1−x−y Si x Sn y layers. The PL peak intensity of the strainrelaxed Ge 1−x Sn x layer decreases by a factor of 1/20 compared to the PL peak intensity of the double heterostructure pseudomorphically grown on a Ge(001) substrate. In addition, PL intensity can be increased by post-deposition annealing owing to decreasing defects.

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Section: Resultsmentioning

confidence: 87%

Optoelectronic properties of high-Si-content-Ge_1−x–ySi_xSn _y /Ge_1−xSn_x/Ge_1−x–ySi_xSn_y double heterostructure

Fukuda¹,

Rainko²,

Sakashita³

et al. 2018

Semicond. Sci. Technol.

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“…It is suggested that these high-density point defects play function as nonradiative recombination centers. 26) As a result, in the H-irradiated Ge 1−x Sn x layer, nonradiative recombination through point defects may be more dominant than radiative recombination with the indirect transition, while radiative recombination with the direct transition is still observable. This is because the radiative recombination with the indirect transition needs a longer recombination time of the microseconds order than that with the direct transition of the nanoseconds order.…”

Section: Resultsmentioning

confidence: 99%

Hydrogen-surfactant-mediated epitaxy of Ge₁₋ _xSn_x layer and its effects on crystalline quality and photoluminescence property

Nakatsuka

Fujinami

Asano

et al. 2016

Jpn. J. Appl. Phys.

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The effect of hydrogen-surfactant-mediated molecular beam epitaxy (MBE) growth of Ge1− x Sn x layer on Ge(001) substrate on crystalline quality and photoluminescence (PL) property has been investigated. The effect of irradiation of atomic hydrogen (H) generated by dissociating molecular hydrogen (H2) were examined during the MBE growth. H irradiation significantly improves the surface morphology with the enhancement of the two-dimensional growth of the Ge1− x Sn x epitaxial layer. Enhanced diffuse scattering is observed in the X-ray diffraction profile, indicating a high density of point defects. In the PL spectrum of the H2-irradiated Ge1− x Sn x layer, two components are observed, suggesting the radiative recombination with both indirect and direct transitions, while one component related to the direct transition is observable in the H-irradiated sample. The postdeposition annealing in nitrogen ambient at as low as 220 °C decreases the PL intensity of the H-irradiated Ge1− x Sn x layer, although the intensity is recovered after annealing at 300 °C, suggesting the annihilation of point defects in the Ge1− x Sn x layer.

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“…4. Measurement data is taken from (16)(17)(18)(19). The temperature dependence of E g is modeled for each material after Varshni (20) as…”

Section: Bandgapmentioning

confidence: 99%

Power Output Improvement of Silicon-Germanium Thermoelectric Generators

Wagner¹,

Span²,

Hölzer³

et al. 2006

ECS Trans.

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We present a technology for thermoelectric generators using large area pn-junctions. Thermally generated carriers are separated by the gradient of the built-in potential caused by the pn-junction. The use of these structures for waste heat recovery implies an externally applied temperature gradient in-plane with the pn-junction which causes a current of both electrons and holes from the heated to the cooled side, where electrical contacts are mounted. The device behavior is strongly influenced by the magnitude and the spatial distribution of the generation rate as well as the local transport properties. We present the influence of the alloy composition on the material properties and possibilities to increase the power output by modification of the local material composition. Furthermore, the influence of intentionally implanted gold atoms as additional generation centers is assessed. Effective optimization of thermoelectric generators requires a powerful simulation environment due to the strong correlation of different mechanisms within the device. We present simulation results obtained by the device and circuit simulator Minimos-NT working in conjunction with the optimization framework Siesta.

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Influence of growth conditions on the photoluminescence of pseudomorphic MBE grown Si1-xGex quantum wells

Cited by 10 publications

References 12 publications

Optoelectronic properties of high-Si-content-Ge_1−x–ySi_xSn _y /Ge_1−xSn_x/Ge_1−x–ySi_xSn_y double heterostructure

Optoelectronic properties of high-Si-content-Ge_1−x–ySi_xSn _y /Ge_1−xSn_x/Ge_1−x–ySi_xSn_y double heterostructure

Hydrogen-surfactant-mediated epitaxy of Ge₁₋ _xSn_x layer and its effects on crystalline quality and photoluminescence property

Power Output Improvement of Silicon-Germanium Thermoelectric Generators

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Influence of growth conditions on the photoluminescence of pseudomorphic MBE grown Si1-xGex quantum wells

Cited by 10 publications

References 12 publications

Optoelectronic properties of high-Si-content-Ge1−x–y Si x Sn y /Ge1−x Sn x /Ge1−x–y Si x Sn y double heterostructure

Optoelectronic properties of high-Si-content-Ge1−x–y Si x Sn y /Ge1−x Sn x /Ge1−x–y Si x Sn y double heterostructure

Hydrogen-surfactant-mediated epitaxy of Ge1− xSnx layer and its effects on crystalline quality and photoluminescence property

Power Output Improvement of Silicon-Germanium Thermoelectric Generators

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Product

Resources

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Optoelectronic properties of high-Si-content-Ge_1−x–ySi_xSn _y /Ge_1−xSn_x/Ge_1−x–ySi_xSn_y double heterostructure

Optoelectronic properties of high-Si-content-Ge_1−x–ySi_xSn _y /Ge_1−xSn_x/Ge_1−x–ySi_xSn_y double heterostructure

Hydrogen-surfactant-mediated epitaxy of Ge₁₋ _xSn_x layer and its effects on crystalline quality and photoluminescence property