Potentiostatic formation of porous silicon in dilute HF: Evidence that nanocrystal size is not restricted by quantum confinement

Wijesinghe, T.L. Sudesh L.; Teo, Ee Jin; Blackwood, Daniel John

doi:10.1016/j.electacta.2008.01.057

Cited by 18 publications

(13 citation statements)

References 26 publications

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“…Theoretically, the effects of quantum confinement on bandgap of silicon indicate that it should be possible to obtain a blue light or shorter wavelength photons from the PS if the Si crystal size can be reduced to a certain value (e.g., to the diameter of 2.0 nm or less) [4][5][6]. However, it is rather difficult in practice to obtain a blue/white PL from the PS even when nanocrystals with diameters smaller than 2.0 nm are present [7]. Wolkin et al [8] attributed this difficulty to the formation of surface Si-O bonds, which lead to mid-bandgap trapped electrons and hole exciton states and thereby remove the dependency of the PL on crystallite size.…”

Section: Introductionmentioning

confidence: 97%

White light luminescence from annealed thin ZnO deposited porous silicon

Kayahan

2010

Journal of Luminescence

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Section: Introductionmentioning

confidence: 97%

White light luminescence from annealed thin ZnO deposited porous silicon

Kayahan

2010

Journal of Luminescence

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“…Another well-known luminescent material is porous Si (pSi); pure pSi’s luminescence is theoretically predicted to be in the range of blue or shorter wavelengths due to quantum confinement 22 . However, experiments have shown that the fabrication of pSi emitting blue or white light is rather difficult, due to the formation of surface Si-O bonds that result in stronger red/yellow luminescence 23 , 24 . Even for the case of pSi nanocrystals smaller than 2.0 nm, where the quantum confinement would be expected to maximize the blue or white emission, the red/yellow emission, due to the Si-O bonds, prevails for geometrical reasons, as the surface to volume ratio of such nanocrystals is also maximized.…”

Section: Introductionmentioning

confidence: 99%

Broadband luminescence in defect-engineered electrochemically produced porous Si/ZnO nanostructures

Dellis

Pliatsikas

Kalfagiannis

et al. 2018

Sci Rep

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The fabrication, by an all electrochemical process, of porous Si/ZnO nanostructures with engineered structural defects, leading to strong and broadband deep level emission from ZnO, is presented. Such nanostructures are fabricated by a combination of metal-assisted chemical etching of Si and direct current electrodeposition of ZnO. It makes the whole fabrication process low-cost, compatible with Complementary Metal-Oxide Semiconductor technology, scalable and easily industrialised. The photoluminescence spectra of the porous Si/ZnO nanostructures reveal a correlation between the lineshape, as well as the strength of the emission, with the morphology of the underlying porous Si, that control the induced defects in the ZnO. Appropriate fabrication conditions of the porous Si lead to exceptionally bright Gaussian-type emission that covers almost the entire visible spectrum, indicating that porous Si/ZnO nanostructures could be a cornerstone material towards white-light-emitting devices.

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“…Furthermore, porous silicon (PS) is also an important semiconductor material, which can be prepared simply by electrochemical etching of silicon in HF solution [15]. Particularly, PS shows high chemical reactivity at room temperature owing to its huge specific surface area [16,17].…”

Section: Introductionmentioning

confidence: 99%