| 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. |
- 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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| 3. |
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| 4. |
- Baranowski, M, et al.
(författare)
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Contactless Electroreflectance, Photoluminescence and Time-Resolved Photoluminescence of GaInNAs Quantum Wells Obtained by the MBE Method with N-irradiation
- 2011
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Ingår i: Semiconductor Science and Technology. - : IOP Publishing. - 1361-6641 .- 0268-1242. ; 26:4, s. 045012-
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Tidskriftsartikel (refereegranskat)abstract
- The optical properties of GaInNAs quantum wells (QW) grown by molecular beam epitaxywith and without N-irradiation (i.e. grown by the classical method) were investigated by thecontactless electroreflectance (CER), temperature-dependent photoluminescence (PL) andtime-resolved PL (TRPL). From CER measurements it was concluded that one type ofnitrogen nearest-neighbor environment (In-rich environment) is dominant for GaInNAs QWsgrown with N-irradiation whereas various nitrogen environments are present for the referenceGaInNAs QW (i.e. the sample obtained by the classical method). PL and TRPL measurementsclearly show that the optical properties of GaInNAs QWs are affected mainly by the amount ofthe incorporated nitride atoms. It was observed that the PL decay time decreased from ∼200to ∼40 ps when the nitrogen concentration is increased from 0.8 to 2.2%. In addition, thepresence of As flux during N-irradiation reduces the amount of the incorporated nitrogen andsimultaneously improves the optical quality of GaInNAs QWs (i.e. it weakens the carrierlocalization at low temperatures and improves the quantum efficiency of PL).
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| 5. |
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| 6. |
- Moschetti, Giuseppe, 1982, et al.
(författare)
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Anisotropic transport properties in InAs/AlSb heterostructures
- 2010
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 97:24, s. 3-
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated the anisotropic transport behavior of InAs/AlSb heterostructures grown on a(001) InP substrate. An electrical analysis showed anisotropic sheet resistance Rsh and electronmobility μn in the two dimensional electron gas (2DEG). Hall measurements demonstrated anenhanced anisotropy in μn when cooled from room temperature to 2 K. High electron mobilitytransistors exhibited 27% higher maximum drain current IDS and 23% higher peak transconductancegm when oriented along the [1-10] direction. The anisotropic transport behavior in the 2DEG wascorrelated with an asymmetric dislocation pattern observed in the surface morphology and bycross-sectional microscopy analysis of the InAs/AlSb heterostructure.
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| 7. |
- Shao, Jun, et al.
(författare)
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Photoluminescence probing of interface evolution with annealing in InGa(N)As/GaAs single quantum wells
- 2015
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 118:16, s. 165305-
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Tidskriftsartikel (refereegranskat)abstract
- The effects of thermal annealing on the interfaces of InGa(N)As/GaAs single quantum wells(SQWs) are investigated by excitation-, temperature-, and magnetic field-dependent photoluminescence(PL). The annealing at 750 °C results in more significant blueshift and narrowing to the PLpeak than that at 600 °C. Each of the PL spectra can be reproduced with two PL components: (i)the low-energy component (LE) keeps energetically unchanged, while the high-energy component(HE) moves up with excitation and shows at higher energy for the In0.375Ga0.625As/GaAs butcrosses over with the LE at a medium excitation power for the In0.375Ga0.625N0.012As0.988/GaAsSQWs. The HE is broader than the corresponding LE, the annealing at 750 °C narrows the LE andHE and shrinks their energetic separation; (ii) the PL components are excitonic, and the InGaNAsshows slightly enhanced excitonic effects relative to the InGaAs SQW; (iii) no typical S-shape evolutionof PL energy with temperature is detectable, and similar blueshift and narrowing are identifiedfor the same annealing. The phenomena are mainly from the interfacial processes. Annealingimproves the intralayer quality, enhances the interfacial In-Ga interdiffusion, and reduces the interfacialfluctuation. The interfacial interdiffusion does not change obviously by the small N contentand hence similar PL-component narrowing and blueshift are observed for the SQWs after a nominallyidentical annealing. Comparison with previous studies is made and the PL measurementsunder different conditions are shown to be effective for probing the interfacial evolution in QWs.
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| 8. |
- Vickers, A. J., et al.
(författare)
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THz Emission Studies on Semiconductor Alloy, InAsBi
- 2016
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Ingår i: International Workshop on Terahertz Science, Nanotechnologies and Applications.
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Konferensbidrag (refereegranskat)abstract
- This paper reports the measurements of the THz emission from InAs films which have been grown by molecular beam epitaxy on a semi-insulating (100) GaAs substrate without, and with different Bi fluxes. The emission is excited with a femtosecond pulsed Er-Fibre laser (λ ~ 1550 nm, 100 fs). The set of InAs film samples are without Bi and with different percentage of Bi. The fs pulsed laser beam is directed onto the sample surface at an angle of incidence 45°. The output THz radiation is collamated through a pair of parabolic lenses through a Germanium detector to remove all non-THz radiation, and finally focussed onto a Microtech Golay cell. An optical chopper set at 20Hz is placed between the collimating optics and the bolometer to provide a reference for a Stanford SR580 lockin amplifier, which takes as an input the Goley cell signal output.
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| 10. |
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