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- Hou, Qichao, et al.
(författare)
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Different Doping Behaviors of Silicon in Zinc Blende and Wurtzite GaAs Nanowires : Implications for Crystal-Phase Device Design
- 2023
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Ingår i: ACS Applied Nano Materials. - 2574-0970. ; 6:13, s. 11465-11471
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Tidskriftsartikel (refereegranskat)abstract
- Crystal-phase engineering between zinc blende (ZB) and wurtzite (WZ) structures is becoming an important method in designing unique optoelectronic and electronic semiconductor devices. Doping to engineer their electric properties is thus of critical importance, but a direct experimental comparison in doping these two crystal structures is still missing. Nanowires (NWs) allow the coexistence of both structures due to their special growth mode. The differences in dopant incorporation between the two phases are studied here in GaAs NW shells that are coherently grown around the NWs, hence maintaining the crystal structure of the core. The Si dopant is observed to have a higher incorporation efficiency into the WZ structure due to a 2 times lower incorporation energy compared with that of the ZB structure. Besides, it can also be predicted that Si is more inclined toward Ga sites in both structures. Indeed, the As-site doping energy of the WZ structure is several orders of magnitude higher than that of Ga sites, allowing a lower doping compensation effect. This work provides useful information for doping control and hence designing crystal-phase devices.
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| 2. |
- Jiang, Pan, et al.
(författare)
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Toward well-defined colloidal particles : Efficient fractionation of lignin by a multi-solvent strategy
- 2024
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Ingår i: International Journal of Biological Macromolecules. - 0141-8130 .- 1879-0003. ; 254:3
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Tidskriftsartikel (refereegranskat)abstract
- Colloidal lignin particles (CLPs) have sparked various intriguing insights toward bio-polymeric materials and triggered many lignin-featured innovative applications. Here, we report a multi-solvent sequential fractionation methodology integrating green solvents of acetone, 1-butanol, and ethanol to fractionate industrial lignin for CLPs fabrication. Through a rationally designed fractionation strategy, multigrade lignin fractions with variable hydroxyl group contents, molecular weights, and high purity were obtained without altering their original chemical structures. CLPs with well-defined morphology, narrow size distribution, excellent thermal stability, and long-term colloidal stability can be obtained by rational selection of lignin fractions. We further elucidated that trace elements (S, N) were reorganized onto the near-surface area of CLPs from lignin fractions during the formation process in the form of -SO42− and -NH2. This work provides a sustainable and efficient strategy for refining industrial lignin into high-quality fractions and an in-depth insight into the CLPs formation process, holding great promise for enriching the existing libraries of colloidal materials.
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