| 1. |
- Chen, Xiren, et al.
(författare)
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Bi-Induced Electron Concentration Enhancement Being Responsible for Photoluminescence Blueshift and Broadening in InAs Films
- 2019
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Ingår i: Physica Status Solidi (B): Basic Research. - : Wiley. - 1521-3951 .- 0370-1972. ; 256:5
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Tidskriftsartikel (refereegranskat)abstract
- Photoluminescence (PL) study is conducted on InAs films molecular beam epitaxially grown on GaAs substrates with different Bi flux levels. A PL peak blueshift accompanied by linewidth broadening is found with the increase of Bi/As flux ratio, in contrast to the common Bi isoelectronic incorporation or surfactant effect. It is, with detailed lineshape analysis and the evidence of PL peak splitting in a magnetic filed, attributed to the electron concentration enhancement induced by Bi flux. The electron concentration in InAs film is evaluated, which is about 5-fold enhanced as Bi/As flux ratio rises up from 0 to 1x10(-3). The temperature dependence of the PL spectrum indicates that the carrier redistribution augments while the carrier-phonon Frohlich scattering weakens in InAs films with high Bi/As flux ratios. These findings reveal a novel Bi effect of electron concentration enhancement, and contribute to the basic knowledge of Bi in III-V semiconductors.
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| 2. |
- Han, Yi, et al.
(författare)
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Abnormal strain in suspended GeSn microstructures
- 2018
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Ingår i: Materials Research Express. - : IOP Publishing. - 2053-1591. ; 5:3
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Tidskriftsartikel (refereegranskat)abstract
- A suspended GeSn microstructure is realized by a two-step selective wet etching technique with the aim of fully relaxing the compressive strain, promoting the indirect to direct bandgap transition and improving the optical property of GeSn thin films grown on Ge. The compressive strain was found efficiently relaxed, and even unexpected large tensile strain was displayed on regions of the microstructure by micro-Raman spectroscopy. Residual Ge patches under the suspended GeSn microstructure were found by scanning electron microscopy and proved to be the origin of the tensile strain by finite element method simulations. The tensile strain on the surface is beneficial for direct bandgap conversion and carrier accumulation. Significant enhancement of photoluminescence was obtained in the GeSn microstructures than the original thin film.
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| 3. |
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