Porous silicon bandgap broadening at natural oxidation

Rustamov, F. A.; Darvishov, N.H.; Mamedov, M.Z.; Bobrova, E.Y.; Qafarova, H.O.

doi:10.1016/j.jlumin.2011.05.040

Cited by 6 publications

(3 citation statements)

References 7 publications

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“…In TIs, topologically protected edge states (TPESs) provide robust wave propagation immune to disturbances and defects. This working concept of TIs has rapidly been extended to other classical fields such as the photonics [2,3,11], acoustics [12][13][14][15], and elastic fields [16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Valley Hall Elastic Edge States in Locally Resonant Metamaterials

et al. 2022

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This paper presents a locally resonant metamaterial periodically rearranged as a local resonator, that is hexagonal holes arranged in a thin plate replace the elastic local resonator to achieve the quantum valley Hall effect. Due to the C3v symmetry in the primitive hexagonal lattice, one Dirac point emerges at high symmetry points in the Brillouin zone in the sub-wavelength area. Rotating the beam element of the resonator can break the spatial inversion symmetry to lift the Dirac degeneracy and form a new bandgap. Thus, the band inversion is discovered by computing the relationship between the associated bandgap and the rotational parameter. We also confirmed this result by analyzing the vortex chirality and calculating the Chern number. We can discover two kinds of edge states in the projected band obtained by computing the supercell composed of different topological microstructures. Finally, the propagation behavior in various heterostructures at low frequencies was analyzed. It is shown that these valley Hall elastic insulators can guide elastic waves along sharp interfaces and are immune to backscattering from defects or disorder. By utilizing elastic resonators, a simple reconfigurable topological elastic metamaterial is realized in the sub-wavelength area.

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Section: Introductionmentioning

confidence: 99%

Valley Hall Elastic Edge States in Locally Resonant Metamaterials

et al. 2022

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“…4(b), an obvious blue-shift for peak C during a 40-day air-exposing of Si-NPA was observed. This may be due to the bandgap enlargement of nc-Si caused by quantum confinement effect [36] because of the size decrease of nc-Si during the oxidation process. [27,37,38] It has been proved that for band-toband transitions occurring in silicon nanostructures, the peak energy as a function of temperature could be well expressed by the Varshni equation [33] 𝐸…”

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confidence: 99%

Temperature-Dependent Photoluminescence of Silicon Nanoporous Pillar Array

Li¹,

Wang²,

Fan³

et al. 2014

Chinese Phys. Lett.

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Silicon nanoporous pillar array (Si-NPA) is a micron-nanometer hierarchical structure which might be used as functional substrates for constructing optoelectronic nanodevices. This makes understanding the photoluminescence (PL) from Si-NPA important. We measure the PL of Si-NPA in the range of 11-300 K. By analyzing the evolution of the peak energy and intensity with temperature, the ultraviolet, blue, orange and red PL bands from Si-NPA are attributed to the radiative recombination through the deep-levels in silicon oxide, oxygen-related defect states in silicon nanocrystallites (nc-Si), band-to-band transition within nc-Si, and surface/interface states of nc-Si or between nc-Si and SiO𝑥, respectively. At least two non-radiative recombination processes, which are activated at different temperature ranges, are proposed for the PL intensity variation with temperature. These results might provide strong foundations for designing and constructing optoelectronic devices based on silicon nanostructures.

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“…In Ref. [16] we have shown that the process of PS formation in this solution had a very good repeatability and reproducibility, independent of the final treatment method. Here, very homogeneous uniformly colored specular PS layers of different thicknesses are obtained.…”

Section: Methodsmentioning

confidence: 72%

Influence of final treatment on the incubation period and antireflection properties of stain‐etched porous silicon

Rustamov

Darvishov

Bagiev

et al. 2013

Physica Status Solidi (a)

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The influence of composition of various solutions, applied for final treatment of Si wafers before stain-etched porous silicon (PS) formation, on the incubation period and antireflective properties has been investigated. PS layers were obtained by chemical etching in HF:HNO 3 :CH 3 COOH modified solution at oxidant insufficiency. It is shown that the minimum incubation period and the reflectivity correspond to the final treatment of wafers in undiluted HF. Studies of reflection spectra have shown the possibility of smooth adjustment of the minimum in the reflection spectra, which is of interest for the formation of antireflection coating for solar cells.

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Porous silicon bandgap broadening at natural oxidation

Cited by 6 publications

References 7 publications

Valley Hall Elastic Edge States in Locally Resonant Metamaterials

Valley Hall Elastic Edge States in Locally Resonant Metamaterials

Temperature-Dependent Photoluminescence of Silicon Nanoporous Pillar Array

Influence of final treatment on the incubation period and antireflection properties of stain‐etched porous silicon

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