| 1. |
- Adnane, Bouchaib, et al.
(författare)
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Origin of photoresponse at 8-14 μm in stacks of self-assembled SiGe/Si quantum dots
- 2009
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- A normal incidence photodetector operating at 8-14 μm is demonstrated using p-type δ-doped SiGe dot multilayer structures grown by molecular beam epitaxy on Si(001) substrates. Based on the experimental results of photoluminescence and photoluminescence excitation spectroscopies together with numerical analysis, the origin of the measured photocurrent was attributed to intersubband optical transitions between the heavy hole and light hole states of the valence band of the self-assembled SiGe dots and subsequent lateral transport of photo-excited carriers in the conduction channels formed by Ge wetting layers.
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| 2. |
- Adnane, Bouchaib, et al.
(författare)
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Photoluminescence excitation spectroscopy of self-assembled SiGe/Si quantum dots
- 2009
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Photoluminescence excitation (PLE) experiments are reported for various self-assembled SiGe/Si dot samples grown on Si(001) by molecular beam epitaxy at substrate temperatures ranging from 430 to 580 C. Two excitation peaks were observed, and the characteristics of the involved optical transitions were studied in detail by PLE (in one case implemented together with selective photoluminescence, SPL) on different samples containing either only one SiGe dot layer or multiple SiGe-dot/Si stacks. The temperature- and power-dependence of the excitation properties together with the results of six-band k.p calculations support the assignment of the observed PLE peaks to spatially direct and indirect transitions collected from two different SiGe dot populations.
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| 3. |
- Adnane, Bouchaib, et al.
(författare)
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Spatially direct and indirect transitions of self-assembled SiGe/Si quantum dots studied by photoluminescence excitation spectroscopy
- 2010
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 96:18, s. 181107-
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Tidskriftsartikel (refereegranskat)abstract
- Well-resolved photoluminescence excitation (PLE) spectra are reported for selfassembled SiGe dots grown on Si(100) by molecular beam epitaxy. The observation of two excitation resonance peaks is attributed to two different excitation/de-excitation routes of interband optical transitions connected to the spatially direct and indirect recombination processes. It is concluded that two dot populations are addressed by each monitored luminescence energy for the PLE acquisition.
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| 4. |
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| 5. |
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| 6. |
- Holtz, Per-Olof, 1951-, et al.
(författare)
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Effects of External Fields on the Excitonic Emission from Single InAs/GaAs Quantum Dots
- 2008
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Ingår i: Microelectronics Journal, Vol. 39. - Microelectronics Journal : Elsevier. ; , s. 331-334
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Konferensbidrag (refereegranskat)abstract
- A low-temperature micro-photoluminescence (μ-PL) investigation of InAs/GaAs quantum dots (QDs) exposed to a lateral external electric field is reported. It is demonstrated that the QDs PL signal could be increased several times by altering the external and/or the internal electric field. The internal field in the vicinity of the dots could be altered by means of an additional infra-red laser. We propose a model, which is based on an essentially faster lateral transport of the charge carriers achieved in an external electric field. Consequently, also the capture probability into the dots and subsequently the dot luminescence is also enhanced. The results obtained suggest that the lateral electric fields play a major role for the dot luminescence intensity measured in our experiment.
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| 7. |
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| 8. |
- Holtz, Per-Olof, 1951-, et al.
(författare)
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Enhanced Luminescence from InAs/GaAs Quantum Dots
- 2006
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Ingår i: Optical Materials in Defence Systems Technology III,2006. - Proceedings of SPIE 6401 : SPIE Digital Library. ; , s. 64010I-
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Konferensbidrag (refereegranskat)
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| 9. |
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| 10. |
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