| 1. |
- Baranowski, M., et al.
(författare)
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Nitrogen-related changes in exciton localization and dynamics in GaInNAs/GaAs quantum wells grown by metalorganic vapor phase epitaxy
- 2015
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Ingår i: Applied Physics A. - : Springer Science and Business Media LLC. - 0947-8396 .- 1432-0630. ; 118:2, s. 479-486
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we show the results of low-temperature photoluminescence (PL), time-resolved photoluminescence, and photoreflectance (PR) investigations, performed on a series of three Ga0.64In0.34As1-x N (x) /GaAs single quantum wells (SQW) grown by metalorganic vapor phase epitaxy with the nitrogen content of 0, 0.5, and 0.8 %. Comparing the PL and PR data, we show that at low excitation intensity and temperature, the radiative recombination occurs via localizing centers (LCs) in all samples. The excitation intensity-dependent PL measurements combined with theoretical modeling of hopping excitons in this system allow us to provide quantitative information on the disorder parameters describing population of LCs. It has been found that the average energy of LCs increases about two times and simultaneously the number of LCs increases about 10 and 20 times after the incorporation of 0.5 and 0.8 % of nitrogen, respectively. The value of average localization energy E > (0) determined for N-containing samples (similar to 6-7 meV) is in the range typical for dilute nitride QWs grown by molecular beam epitaxy (MBE). On the other hand, the "effective" concentration of LCs seems to be higher than for GaInNAs/GaAs QW grown by MBE. The dramatic increase in localizing centers also affects the PL dynamics. Observed PL decay time dispersion is much stronger in GaInNAs SQW than in nitrogen-free SQW. The change in PL dynamic is very well reproduced by model of hopping excitons.
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| 2. |
- Gelczuk, L., et al.
(författare)
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Bi-induced acceptor level responsible for partial compensation of native free electron density in InP1-xBix dilute bismide alloys
- 2016
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Ingår i: Journal of Physics D: Applied Physics. - : IOP Publishing. - 1361-6463 .- 0022-3727. ; 49:11
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Tidskriftsartikel (refereegranskat)abstract
- Deep level transient spectroscopy (DLTS) has been applied to study electron and hole traps in InPBi alloys with 2.2 and 2.4% Bi grown by molecular beam epitaxy. One donor-like trap with the activation energy of 0.45-0.47 eV and one acceptor-like trap with activation energy of 0.08 eV have been identified in DLTS measurements. For the reference sample (InP grown at the same temperature), the deep donor trap has also been observed, while the acceptor trap was not detected. According to the literature, the deep donor level found in InP(Bi) at 0.45-0.47 eV below the conduction band has been attributed to the isolated P-In defect, while the second trap, which is observed only for Bi containing samples at 0.08 eV above the valence band can be attributed to Bi clusters in InPBi. This acceptor level was proposed to be responsible for the observed partial compensation of native free electron density in InPBi layers. It is also shown that the deep donor traps are active in photoluminescence (PL). A strong radiative recombination between donor traps and the valence band are observed in PL spectra at energy 0.6-0.8 eV, i.e. similar to 0.47 eV below the energy gap of InPBi, which is determined by contactless electroreflectance.
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| 3. |
- Wang, Shu Min, 1963, et al.
(författare)
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Dilute bismide and nitride alloys for mid-IR optoelectronic devices
- 2019
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Ingår i: Mid-infrared Optoelectronics: Materials, Devices, and Applications. ; , s. 457-492
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Dilute bismide and nitride provide flexible bandgap and strain engineering, owing to their unique physical properties, and are attractive for mid-IR (2-12 µm) optoelectronic device applications. In this chapter, we review progresses of theoretical simulations, epitaxial growth, material characterizations, and devices of dilute bismides including GaSbBi, AlSbBi, InAsBi, InAsSbBi, InGaAsBi, and InSbBi, as well as dilute nitrides including InNAs, GaNSb, InNSb, GaInNAs, and InNAsSb. The overview mainly focuses on growth optimization, optical characterizations, and theoretical calculations ending with outlook remarks about advantages and main challenges of both exotic materials.
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| 4. |
- Yue, L., et al.
(författare)
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Structural and optical properties of GaSbBi/GaSb quantum wells [Invited]
- 2018
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Ingår i: Optical Materials Express. - 2159-3930. ; 8:4, s. 893-900
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Tidskriftsartikel (refereegranskat)abstract
- GaSbBi/GaSb quantum wells (QWs) with Bi content up to 10.1% were grown using molecular beam epitaxy. High crystalline quality and clear interfaces were confirmed by high resolution transmission electron microscopy. The Bi distribution was investigated using energy dispersive X-ray spectroscopy. Room temperature photoluminescence (PL) reveals that the peak energy redshifts at a rate of 32 meV/Bi%, consistent with the theoretical predication using the 8-band kp model. From the temperature dependent PL, it was found that the temperature-insensitivity of the transition from the GaSbBi QW improved with increasing Bi content.
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