| 11. |
- Song, Yuxin, 1981, et al.
(author)
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Natural patterning of templates on GaAs by formation of cracks
- 2015
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In: AIP Advances. - : AIP Publishing. - 2158-3226 .- 2158-3226. ; 5:6, s. Art Nr 067146-
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Journal article (peer-reviewed)abstract
- Substrate pre-patterning is an effective way to overcome large lattice mismatch and suppress threading defects in the growth of heterostructures. In this work, a new concept was proposed to form natural patterns on commercial substrates monolithically by the formation of surface cracks. Tensile strain was intentionally brought in with a GaAs or GaNAs layer above an InGaAs layer on GaAs substrates. Surface crack patterns successfully formed during the strain relaxation. The strain in a 1 μm buffer layer atop the pattern was found effectively relaxed. Detailed residual strain distribution was simulated by the finite element method.
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| 12. |
- Wang, Shu Min, 1963, et al.
(author)
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Electrically pumped GaAsBi laser diodes
- 2017
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In: International Conference on Transparent Optical Networks. - 2162-7339. - 9781538608586
-
Conference paper (peer-reviewed)abstract
- In this paper, we present electrically pumped GaAsBi quantum well (QW) laser diodes (LDs) grown by molecular beam epitaxy. The LDs reveal a record long lasing wavelength of 1.14 μm at 300 K and can be operated under CW excitation up to 273 K. They also show high performance with an internal quantum efficiency of 86% and an internal optical loss of 10 cm-1. The characteristic temperature is 79 K in the temperature range of 225-350 K and the temperature coefficient of the lasing wavelength is 0.26 nm/K at 77 - 350 K, much smaller than 0.35 - 0.40 nm/K for InGaAs and InGaAsP QW LDs. These results suggest that GaAsBi LDs are attractive candidates for uncooled near infrared lasers on GaAs.
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| 13. |
- Wiesner, M., et al.
(author)
-
The electron-phonon interaction at deep Bi 2 Te3-semiconductor interfaces from Brillouin light scattering
- 2017
-
In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 7:1
-
Journal article (peer-reviewed)abstract
- It is shown that the electron-phonon interaction at a conducting interface between a topological insulator thin film and a semiconductor substrate can be directly probed by means of high-resolution Brillouin light scattering (BLS). The observation of Kohn anomalies in the surface phonon dispersion curves of a 50 nm thick Bi2Te3 film on GaAs, besides demonstrating important electron-phonon coupling effects in the GHz frequency domain, shows that information on deep interface electrons can be obtained by tuning the penetration depth of optically-generated surface phonons so as to selectively probe the interface region, as in a sort of quantum sonar.
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| 14. |
- Wu, L., et al.
(author)
-
Structural and electronic properties of two-dimensional stanene and graphene heterostructure
- 2016
-
In: Nanoscale Research Letters. - : Springer Science and Business Media LLC. - 1556-276X .- 1931-7573. ; 11:1, Artikel nr: 525
-
Journal article (peer-reviewed)abstract
- Structural and electronic properties of two-dimensional stanene and graphene heterostructure (Sn/G) are studied by using first-principles calculations. Various supercell models are constructed in order to reduce the strain induced by the lattice mismatch. The results show that stanene interacts overall weakly with graphene via van der Waals (vdW) interactions. Multiple phases of different crystalline orientation of stanene and graphene could coexist at room temperature. Moreover, interlayer interactions in stanene and graphene heterostructure can induce tunable band gaps at stanene’s Dirac point, and weak p-type and n-type doping of stanene and graphene, respectively, generating a small amount of electron transfer from stanene to graphene. Interestingly, for model Sn(7)/G(5), there emerges a band gap about 34 meV overall the band structure, indicating it shows semiconductor feature.
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| 15. |
- Wu, X. Y., et al.
(author)
-
Effect of rapid thermal annealing on InP1-xBix grown by molecular beam epitaxy
- 2015
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In: Semiconductor Science and Technology. - : IOP Publishing. - 1361-6641 .- 0268-1242. ; 30:9
-
Journal article (peer-reviewed)abstract
- The effect of post-growth rapid thermal annealing on structural and optical properties of InP1-xBix thin films was investigated. InPBi shows good thermal stability up to 500 °C and a modest improvement in photoluminescence (PL) intensity with an unchanged PL spectral feature. Bismuth outdiffusion from InPBi and strain relaxation are observed at about 600 °C. The InPBi sample annealed at 800 °C shows an unexpected PL spectrum with different energy transitions.
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| 16. |
- Xu, H., et al.
(author)
-
Vibrational properties of epitaxial Bi4Te3 films as studied by Raman spectroscopy
- 2015
-
In: AIP Advances. - : AIP Publishing. - 2158-3226 .- 2158-3226. ; 5:8
-
Journal article (peer-reviewed)abstract
- Bi4Te3, as one of the phases of the binary Bi-Te system, shares many similarities with Bi2Te3, which is known as a topological insulator and thermoelectric material. We report the micro-Raman spectroscopy study of 50 nm Bi4Te3 films on Si substrates prepared by molecular beam epitaxy. Raman spectra of Bi4Te3 films completely resolve the six predicted Raman-active phonon modes for the first time. Structural features and Raman tensors of Bi4Te3 films are introduced. According to the wavenumbers and assignments of the six eigenpeaks in the Raman spectra of Bi4Te3 films, it is found that the Raman-active phonon oscillations in Bi4Te3 films exhibit the vibrational properties of those in both Bi and Bi2Te3 films.
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| 17. |
- Yue, Li, et al.
(author)
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Novel type II InGaAs/GaAsBi quantum well for longer wavelength emission
- 2017
-
In: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388. ; 695, s. 753-759
-
Journal article (peer-reviewed)abstract
- We propose a new type II InGaAs/GaAsBi quantum well structure to extend light emission wavelength on GaAs and demonstrate the effect experimentally. Type II InGaAs/GaAsBi QWs were grown using molecular beam epitaxy. Room temperature photoluminescence confirms wavelength extension to 1230 nm, 82 and 208 nm longer than that of the type I GaAsBi and InGaAs QW with the same Bi or In content, respectively. The PL intensity is enhanced by more than ten times than the GaAsBi QW. Our results show that the type II dilute bismide QW has potentials for making telecom lasers on GaAs.
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| 18. |
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| 19. |
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| 20. |
- Zhu, Z. Y. S., et al.
(author)
-
GeSn/Ge dual-nanowire heterostructure
- 2017
-
In: 2017 IEEE Photonics Society Summer Topicals Meeting Series, SUM 2017; San Juan Marriott ResortSan Juan; Puerto Rico; 10 July 2017 through 12 July 2017. - 9781509065707 ; , s. 71-72
-
Conference paper (peer-reviewed)abstract
- A dual-nanowire heterostructure with a GeSn layer laterally laying on Ge nanowires is demonstrated by MBE. The strain field analyzed by FEM shows that the novel proposal can significantly release the compressive strain in GeSn for potential direct bandgap conversion as a Si-based light source.
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