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| 2. |
- Aad, G., et al.
(författare)
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- 2012
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Chen, Q., et al.
(författare)
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Highly Tensile-Strained Self-Assembled Ge Quantum Dots on InP Substrates for Integrated Light Sources
- 2021
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Ingår i: ACS Applied Nano Materials. - : American Chemical Society (ACS). - 2574-0970. ; 4:1, s. 897-906
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Tidskriftsartikel (refereegranskat)abstract
- Highly tensile-strained Ge quantum dots (TS-Ge-QDs) emitting structures with different size were successfully grown on InP substrates by molecular beam epitaxy. Dislocation-free TS-Ge-QDs were observed by transmission electron microscopy. Finite element modeling indicates a maximum tensile strain of 4.5% in the Ge QDs, which is much larger than the required strain to achieve direct band gap conversion of Ge based on theoretical prediction. Photoluminescence (PL) from a direct band-gap-like transition of TS-Ge-QDs with a peak energy of 0.796 eV was achieved and confirmed by the etch depth-dependent PL, temperature-dependent PL, and excitation-power-dependent PL. In addition, a strong defect-related peak of 1 eV was observed at room temperature. The band structure of the TS-Ge-QDs emitting structures was calculated to support the experimental results of PL spectra. Achieving PL from direct band-gap-like transitions of TS-Ge-QDs provides encouraging evidence of this promising highly tensile strained semiconductor-nanostructure-based platform for future photonics applications such as integrated light sources.
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| 4. |
- Chen, X, et al.
(författare)
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Negative thermal quenching of below-bandgap photoluminescence in InPBi
- 2017
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 110:5
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports a temperature-dependent (10-280 K) photoluminescence (PL) study of below-bandgap electron-hole recombinations and anomalous negative thermal quenching of PL intensity in InP1- xBix (x = 0.019 and 0.023). Four PL features are well resolved by curve-fitting of the PL spectra, of which the energies exhibit different temperature dependence. The integral intensities of the two high-energy features diminish monotonically as temperature rises up, while those of the two low-energy features decrease below but increase anomalously above 180 K. A phenomenological model is established that the residual electrons in the final state of the PL transition transfer into nonradiative state via thermal hopping, and the thermal hopping produces in parallel holes in the final state and hence enhances the radiative recombination significantly. A reasonable interpretation of the PL processes in InPBi is achieved, and the activation energies of the PL quenching and thermal hopping are deduced. © 2017 Author(s).
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| 5. |
- Liu, Juanjuan, et al.
(författare)
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Electrically injected GaAsBi/GaAs single quantum well laser diodes
- 2017
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Ingår i: AIP Advances. - : AIP Publishing. - 2158-3226 .- 2158-3226. ; 7:11, s. Article Number: 115006 -
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Tidskriftsartikel (refereegranskat)abstract
- We present electrically injected GaAs/GaAsBi single quantum well laser diodes (LDs) emitting at a record long wavelength of 1141 nm at room temperature grown by molecular beam epitaxy. The LDs have excellent device performances with internal quantum efficiency of 86%, internal loss of 10 cm-1 and transparency current density of 196 A/cm2. The LDs can operate under continuous-wave mode up to 273 K. The characteristic temperature are extracted to be 125 K in the temperature range of 77?150 K, and reduced to 90 K in the range of 150?273 K. The temperature coefficient of 0.3 nm/K is extracted in the temperature range of 77?273 K.
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| 6. |
- Wang, Shu Min, 1963, et al.
(författare)
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Novel Dilute Bismides for IR Optoelectronics Applications
- 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
- III-V-Bi compounds reveal a number of attractive physical properties promising for novel IR optoelectronic applications [1,2] and have received considerable attention as witnessed by the dedicated international workshops on this topic in the consecutive past four years. The isoelectronic nature of Bi atoms in III-Vs induces strong interactions with the energy bands of host materials leading to large band-gap reduction, less temperature sensitive band-gap and large spin-orbit split band. So far the most studied material is Ga(N)AsBi, while other dilute bismides have also been reported recently. In this paper, we shall briefly review several novel bismides: GaSbBi, InSbiBi, InAsBi, InPBi and InGaAsBi, and the Bi surfactant effect from our group, all grown by molecular beam epitaxy (MBE).
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| 7. |
- Wu, Xiaoyan, et al.
(författare)
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Anomalous photoluminescence in InP1-xBix
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 6, s. Art. no. 27867-
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Tidskriftsartikel (refereegranskat)abstract
- Low temperature photoluminescence (PL) from InP1-xBix thin films with Bi concentrations in the 0-2.49% range reveals anomalous spectral features with strong and very broad (linewidth of 700 nm) PL signals compared to other bismide alloys. Multiple transitions are observed and their energy levels are found much smaller than the band-gap measured from absorption measurements. These transitions are related to deep levels confirmed by deep level transient spectroscopy, which effectively trap free holes and enhance radiative recombination. The broad luminescence feature is beneficial for making super-luminescence diodes, which can theoretically enhance spatial resolution beyond 1 ?m in optical coherent tomography (OCT).
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| 8. |
- Yue, Li, et al.
(författare)
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Novel type II InGaAs/GaAsBi quantum well for longer wavelength emission
- 2017
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Ingår i: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388. ; 695, s. 753-759
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Tidskriftsartikel (refereegranskat)abstract
- We propose a new type II InGaAs/GaAsBi quantum well structure to extend light emission wavelength on GaAs and demonstrate the effect experimentally. Type II InGaAs/GaAsBi QWs were grown using molecular beam epitaxy. Room temperature photoluminescence confirms wavelength extension to 1230 nm, 82 and 208 nm longer than that of the type I GaAsBi and InGaAs QW with the same Bi or In content, respectively. The PL intensity is enhanced by more than ten times than the GaAsBi QW. Our results show that the type II dilute bismide QW has potentials for making telecom lasers on GaAs.
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| 10. |
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