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- 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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| 2. |
- 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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| 3. |
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| 4. |
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| 5. |
- Song, Yuxin, 1981
(författare)
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Novel Materials and Technologies for IR Optoelectronic Applications
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis focuses on novel III-V materials (InAs/GaSb type-II superlattices, T2SL, and dilute bismides) and metamorphic growth techniques for infrared optoelectronics all of which may find wide spread applications in telecommunication, energy harvesting and saving, sensing and imaging. Mid-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) photodetectors at the atmospheric windows of 3-5 and 8-12 µm, respectively, are currently dominated by HgCdTe and quantum well infrared photodetectors. These detectors, however, suffer from the suitability for making focal plane array (FPA) detectors due to the material non-uniformity or the low operation temperature that significantly increases the cost for a practical detection or imaging system. InAs/GaSb type-II superlattices are promising candidates for FPA detectors with better performance at a lower cost. Dilute bismides where a small amount of Bi atoms are incorporated into traditional host III-V semiconductors have theoretically shown a number of interesting physical properties. The large energy band bowing effect with retained transport and optical properties make these materials attractive for making short-wavelength infrared (SWIR), MWIR and LWIR optoelectronic devices. Dilute bismides have been only little studied among the III-V semiconductors, and in particular epitaxial growth of dilute III-SbBi is almost unexplored. Metamorphic growth is an efficient technique for lattice engineering and useful for device applications such as multi-junction solar cells, III-V and Si integration, electronic and optoelectronic devices on cheap substrates. Here, growth optimization and innovations to minimize threading dislocations are challenging and crucial for improving the material quality.The work in this thesis deals with issues related to the realization of these novel III-V materials and metamorphic growth techniques using molecular beam epitaxy (MBE). It is investigated how doping in alloy graded metamorphic buffers influences material quality and a new method to reduce dislocation density and improve optical quality by using dilute nitride buffer layers is demonstrated. Design and growth optimization of T2SL structures for mid-IR detectors are presented. MBE growth of novel dilute III-SbBi alloys is investigated. The growth of GaSbBi is reported for the first time. The abnormal lattice contraction of GaSbBi is discovered and explained.
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| 6. |
- Ye, Hong, 1987, et al.
(författare)
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Light emission from InGaAs:Bi/GaAs quantum wells at 1.3 μm
- 2012
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Ingår i: AIP Advances. - : AIP Publishing. - 2158-3226 .- 2158-3226. ; 2:4, s. 042158-
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Tidskriftsartikel (refereegranskat)abstract
- Highly strained InGaAs:Bi quantum wells (QWs) were grown on (001)-oriented GaAs substrates by molecular beam epitaxy (MBE). Photoluminescence (PL) reveals strong improvements in the optical properties evidenced by 10 times enhancement in PL intensity and extended emission wavelength up to 1.29 μm when Bi is introduced to InGaAs/GaAs QWs. The improved optical quality results from the Bi surfactant effect as well as the Bi incorporation. Post growth thermal annealing shows that Bi atoms in InGaAs/GaAs QWs do not show good thermal stability at 650 °C and tend to diffuse out of the QWs resulting in large wavelength blue-shifts.
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