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- Mergenthaler, K., et al.
(författare)
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Anti-Stokes photoluminescence probing k-conservation and thermalization of minority carriers in degenerately doped semiconductors
- 2017
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- It has recently been found that anti-Stokes photoluminescence can be observed in degenerately n-doped indium phosphide nanowires, when exciting directly into the electron gas. This anti-Stokes mechanism has not been observed before and allows the study of carrier relaxation and recombination using standard photoluminescence techniques. It is important to know if this anti-Stokes photoluminescence also occurs in bulk semiconductors as well as its relation to carrier recombination and relaxation. Here we show that similar anti-Stokes photoluminescence can indeed be observed in degenerately doped bulk indium phosphide and gallium arsenide and is caused by minority carriers scattering to high momenta by phonons. We find in addition that the radiative electron-hole recombination is highly momentum-conserving and that photogenerated minority carriers recombine before relaxing to the band edge at low temperatures. These observations challenge the use of models assuming thermalization of minority carriers in the analysis of highly doped devices.
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| 4. |
- Monemar, B, et al.
(författare)
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Magnetic properties of bound hole states for complex neutral defects in semiconductors
- 1986
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Ingår i: Journal of Luminescence. - : Elsevier BV. - 0022-2313 .- 1872-7883. ; 36:3, s. 149-159
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Tidskriftsartikel (refereegranskat)abstract
- The magnetic properties of an electron-hole pair bound to complex neutral defects in semiconductors are discussed and compared to experimental data for both direct- and indirect-bandgap materials. The properties of bound hole states for such defects are discussed in a general formalism, which avoids the generally inadequate effective-mass-like description often used in previous literature. In the case of low symmetry defects with a dominantly hole-attractive local potential the primary bound hole state is often nondegenerate and shows a spin-like character with a quenched angular momentum. This case has recently been demonstrated experimentally for a large number of defects in GaP and Si. A strong spin-orbit interaction may inhibit such a quenching so that the bound hole angular momentum is at least partly retained. This situation often prevails for complex defects in materials like CdTe and ZnTe, where the valence band spin-orbit splitting Δso is large. For electron-attractive central cell potentials, the bound hole state is generally effective-mass-like, and retains its anisotropic magnetic behaviour due to the hole angular momentum. Experimental data supporting this situation are also demonstrated, for both Si and compound semiconductors.
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| 7. |
- Nemec, H., et al.
(författare)
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Bulk-like transversal electron mobility in heavily n-doped InP nanowires probed by terahertz spectroscopy
- 2014
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Ingår i: 2014 39th International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz 2014. - 9781479938773
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Konferensbidrag (refereegranskat)abstract
- Waveguiding of excitation beam and propagation of THz beam in a complex gradient environment were studied in an array of InP nanowires. Measurements by time-resolved THz spectroscopy accompanied by Monte-Carlo calculations of the response of localized charges enabled determination of transversal electron mobility.
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| 8. |
- Zwiller, V., et al.
(författare)
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Studies of self-assembled InP quantum dots in planar microcavities
- 2000
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Ingår i: Materials Science and Engineering B: Solid-State Materials for Advanced Technology. - Strasbourg, France. ; 69:Lausanne, Switzerland, s. 314-317
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Tidskriftsartikel (refereegranskat)abstract
- Self-assembled InP quantum dots have been grown in planar microcavities. The dots were embedded in a Ga0.52In0.48P spacer grown on top of a high reflectance epitaxial Al0.29Ga0.71As/AlAs distributed Bragg reflector (DBR) to obtain a 33λ/4 cavity. The Fabry-Perot microcavity is formed between the AlGaAs/AlAs DBR and a dielectric SiNx/SiO2 DBR deposited on top of the GaInP spacer. The quantum dot emission is centered at 1.62 eV at 7 K. The microcavity resonance is centered at 1.65 eV, with a linewidth of 2 meV. Micro-photoluminescence (PL) studies using different objectives with different numerical apertures enable the collection of transversal modes.
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