| 1. |
- Zhang, Bin, et al.
(författare)
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Effect of exciton transfer on recombination dynamics in vertically nonuniform GaAsSb epilayers
- 2019
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Ingår i: Applied Physics Letters. - : AMER INST PHYSICS. - 0003-6951 .- 1077-3118. ; 114:25
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Tidskriftsartikel (refereegranskat)abstract
- Low-temperature photoluminescence (PL), photoreflectance (PR), and temperature dependent time-resolved PL spectroscopies are employed to investigate optical emission processes and exciton dynamics in graded GaAsSb epilayers. The nonuniformity in the Sb composition along the growth direction is disclosed by low-temperature PL and PR measurements. Furthermore, significant differences in PL dynamics are found at low temperatures for the PL emissions originating from spatial regions with the low and high Sb compositions, with a fast decay and a slow rise at the early stage of the PL transient, respectively. This finding is attributed to exciton transfer from the low Sb region to the high Sb region. The obtained results are important for a general understanding of optical transitions and exciton/carrier dynamics in material systems with a graded alloy composition.
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| 2. |
- Zhang, Bin, et al.
(författare)
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Anomalously Strong Second‐Harmonic Generation in GaAs Nanowires via Crystal‐Structure Engineering
- 2021
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Ingår i: Advanced Functional Materials. - Weinheim, Germany : Wiley-V C H Verlag GMBH. - 1616-301X .- 1616-3028. ; 31:36
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Tidskriftsartikel (refereegranskat)abstract
- GaAs-based semiconductors are highly attractive for diverse nonlinear photonic applications, owing to their non-centrosymmetric crystal structure and huge nonlinear optical coefficients. Nanostructured semiconductors, for example, nanowires (NWs), offer rich possibilities to tailor nonlinear optical properties and further enhance photonic device performance. In this study, it is demonstrated highly efficient second-harmonic generation in subwavelength wurtzite (WZ) GaAs NWs, reaching 2.5 × 10−5 W−1, which is about seven times higher than their zincblende counterpart. This enhancement is shown to be predominantly caused by an axial built-in electric field induced by spontaneous polarization in the WZ lattice via electric field-induced second-order nonlinear susceptibility and can be controlled optically and potentially electrically. The findings, therefore, provide an effective strategy for enhancing and manipulating the nonlinear optical response in subwavelength NWs by utilizing lattice engineering.
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| 3. |
- Wang, Hongzhen, et al.
(författare)
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Effects of substrate temperature on the uniformity of InGaAs epilayers using a dual-zone manipulator
- 2021
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Ingår i: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248. ; 574
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Tidskriftsartikel (refereegranskat)abstract
- Three-inch InGaAs epilayers are grown by solid source molecular beam epitaxy using the manipulator equipped with dual-zone heaters. The effects of the substrate temperature on the uniformity of material surface morphology, indium composition, photoluminescence, electronic mobility, and background doping are investigated. As the temperature of the outer heater in the range of 625 °C to 655 °C, no dim area is observed on the edge of the material surface. At the same time, the indium composition fluctuation of the high-resolution X-ray diffraction and the photoluminescence wavelength fluctuation are less than ±0.1% for the epilayers grown at the optimum substrate temperatures.
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| 4. |
- Zhao, Yadong, 1985-, et al.
(författare)
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Enhancement of myofibrillar protein gelation by plant proteins for improved surimi gel characteristics: Mechanisms and performance
- 2024
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Ingår i: Lebensmittel-Wissenschaft + Technologie. - : Elsevier BV. - 0023-6438 .- 1096-1127. ; 198
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Tidskriftsartikel (refereegranskat)abstract
- Three commonly used plant proteins, soy isolate protein (SPI), wheat gluten (WG) and pea protein (PP), were incorporated into surimi gels, and their effects on myofibrillar protein gelation and resultant surimi gel properties have been investigated. Results revealed that addition of any of these plant proteins at 5 g/100 g surimi enhanced the surimi gelation, among which SPI addition resulted in smoother, denser and whiter surimi gels (whiteness of 61.49) with superior textural attributes (hardness of 1994 g), water-holding capacity (85.67%) and structural integrity. Such improvements were attributed to the uniform distribution of SPI solution between adjacent surimi protein molecules, not only aiding in maintaining the matrix's continuity but bridging the interaction between the proteins. SPI with a higher content of charged amino acids (47.17%) exhibited a better ability to interact with the charged N- and C- terminals of surimi proteins. This interaction promoted the complete unfolding of surimi proteins, facilitated the conversion of α-helix to β structures, exposing hydrophobic ends and sulfhydryl groups, and consequently enhanced the formation of hydrophobic interactions and disulfide bonds during gelation. This study demonstrated that plant proteins, especially SPI, are effective gel-reinforcing additives in surimi gels, offering insights for developing plant protein-rich surimi products.
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