| 21. |
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| 22. |
- Song, Yuxin, 1981, et al.
(författare)
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Effects of doping and grading slope on surface and structure of metamorphic InGaAs buffers on GaAs substrates
- 2009
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 106:12, s. 123531-
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the effects of doping and grading slope on the surface and structure of linearly alloy graded InGaAs buffers. It is found that the Be doping can improve material properties, resulting in smaller surface roughness and a lower threading dislocation density, while the Si doping has an opposite effect. The effect is strongly dependent on the grading slope. A moderate In grading slope is preferable for the strain relaxation and the minimization of the negative effect of Si doping. Physical mechanisms are proposed to explain the experimental observations. Since doping is essential for many types of optoelectronic devices, these results are valuable for improving the material properties and performance of metamorphic devices.
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| 23. |
- Song, Yuxin, 1981, et al.
(författare)
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Enhancement of optical quality in metamorphic quantum wells using dilute nitride buffers
- 2010
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 97:9, s. 091903-
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Tidskriftsartikel (refereegranskat)abstract
- Strong enhancement of optical quality in quantum wells by incorporating nitrogen in metamorphic InGaAs buffers grown on GaAs substrates is demonstrated. This has resulted in 3.7 or 5.4 times enhancement of photoluminescence intensity from the metamorphic quantum wells when using dilute nitride superlattice alone or adding nitrogen in a strain compensated GaAs/In0.3Al0.7As superlattice, respectively. This study shows great potentials by incorporating N in metamorphic buffers to further improve the quality of metamorphic optoelectronic devices.
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| 24. |
- Song, Yuxin, 1981, et al.
(författare)
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Growth of GaSb1-xBix by molecular beam epitaxy
- 2012
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Ingår i: Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures. - : American Vacuum Society. - 2166-2754 .- 2166-2746. ; 30:2, s. 02B114-
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Tidskriftsartikel (refereegranskat)abstract
- Molecular beam epitaxy for GaSb1-xBix is investigated in this article. The growth window for incorporation of Bi in GaSb was found. Strategies of avoiding formation of Bi droplets and enhancing Bi incorporation were studied. The Bi incorporation was confirmed by SIMS and RBS measurements. The Bi concentration in the samples was found to increase with increasing growth temperature and Bi flux. The position of GaSb1-xBix layer peak in XRD rocking curves is found to be correlated to Bi composition. Surface and structural properties of the samples were also investigated. Samples grown on GaSb and GaAs substrates were compared and no apparent difference for Bi incorporation was found.
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| 25. |
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| 26. |
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| 27. |
- Song, Yuxin, 1981, et al.
(författare)
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Investigation of metamorphic InGaAs quantum wells using N-incorporated buffer on GaAs grown by MBE
- 2011
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Ingår i: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248. ; 323:1, s. 21-25
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Tidskriftsartikel (refereegranskat)abstract
- Strong enhancement of photoluminescence intensity from InGaAs quantum wells by incorporating nitrogen in metamorphic InGaAs buffers grown on GaAs substrates was demonstrated and investigated. The enhancement of photoluminescence intensity is found to be from both the weak strain effect and the strong lattice hardening effect, indicating blocking effect of threading dislocations due to the N incorporation. Combination of this method with a strain compensated superlattice was proved to be effective in obtaining good quality metamorphic InGaAs quantum wells.
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| 28. |
- Song, Yuxin, 1981, et al.
(författare)
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MBE growth of Bi2Te3 for Thermoelectrics
- 2013
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Ingår i: Asia Communications and Photonics Conference, ACP. - Washington, D.C. : OSA. - 2162-108X.
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Konferensbidrag (refereegranskat)abstract
- Molecular beam epitaxy of Bi2Te3 on various substrates for thermoelectric applications is investigated. Growth conditions were optimized based on Si(111) substrates with two different growth techniques, co-deposition followed by crystallization and direct growth. Growth of Bi 2Te3 on GaAs, GaN, et. al. substrates with different crystal directions and offcut angles were investigated. High quality Bi2Te3 thin films were achieved with very low carrier density and record high carrier mobility.
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| 29. |
- Song, Yuxin, 1981, et al.
(författare)
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Metamorphic Quantum Well Lasers
- 2012
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Ingår i: Lattice Engineering: Technology and Applications. ; , s. 283-317
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter provides an overview of long wavelengthmetamorphic quantum well lasers. The idea of metamorphic growth is to compromise large lattice mismatch by utilizing a relaxed buffer layer. Structural design and growth optimization of metamorphic buffer layers are reviewed with emphasis on composition grading scheme and doping effects. Progress on long wavelength (>1.2 μm) metamorphic quantum well lasers is summarized.
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| 30. |
- Song, Yuxin, 1981, et al.
(författare)
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Molecular Beam Epitaxy Growth of GaSbxBi1-x
- 2011
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Ingår i: 28th North American Molecular Beam Epitaxy Conference (NAMBE2011), San Diego, USA (2011)..
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Konferensbidrag (refereegranskat)
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