A periodic array of silicon pillars fabricated by photoelectrochemical etching

Li, Xiaopeng; Seo, Hong-Seok; Um, Han‐Don; Jee, Sang-Won; Cho, Yong Woo; Yoo, Bongyoung; Lee, Jung-Ho

doi:10.1016/j.electacta.2009.06.094

Cited by 23 publications

(7 citation statements)

References 27 publications

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“…Such tapering processes were reported to originate from the higher etching rate in the h110i direction over the h100i direction at the top of the SiNWs. 10,11 SiNWs with small diameters (o50 nm) can be easily removed during this process. Increasing further the KOH etching time led to a continuous dissolution of SiNWs along with a rapid decrease in an areal density of SiNWs.…”

Section: Formation Of Tapered Sinws and Their Optical Propertiesmentioning

confidence: 99%

Photoelectrochemical hydrogen evolution of tapered silicon nanowires

Xiao

Zhou

et al. 2015

Phys. Chem. Chem. Phys.

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The origin of the photocurrent enhancement and the overpotential reduction in solar water splitting employing nanostructured silicon is still a matter of debate. A set of tapered Si nanowires (SiNWs) has been designed for clarifying the impact of nanostructured Si on the hydrogen evolution reaction (HER) while precisely tailoring several interference factors such as surface area, light absorption and surface defect density. We find that defect passivation by KOH achieved by tapering is much more beneficial than the optical gain. Surfactant-mediated modification of SiNWs is capable of engineering the band structure. As a result, we suggest a guideline for nanostructured Si photoelectrodes optimized for the HER.

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Section: Formation Of Tapered Sinws and Their Optical Propertiesmentioning

confidence: 99%

Photoelectrochemical hydrogen evolution of tapered silicon nanowires

Xiao

Zhou

et al. 2015

Phys. Chem. Chem. Phys.

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“…and/or chemical composition of the PSi layers. This success is partially due its cost-effectiveness and simpler production equipment [7] in comparison with the other techniques of fabricating PSi (i.e. deep reactive ion etching (DRIE), chemically enhanced laser ablation and metal-assisted chemical etching), and partially due to ease in manipulating the surface structure and morphology through electrochemical condition [8][9][10][11] or experimental parameters [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Effect of surfactant and etching time on p-type porous silicon formation through potentiostatic anodization

Zeb¹,

Le²

2022

Adv. Nat. Sci: Nanosci. Nanotechnol.

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Electrochemical anodization provides the scalability required for structuring porous silicon (PSi) layers for mass production; hence, new and feasible processes are highly sought-after. We investigate the effect of surfactant (additive) and etching time on the morphology of PSi matrix in a simplistic two-electrode anodization cell using aqueous HF electrolyte. Instead of the conventional galvanostatic mode (constant current density), we use the rarely reported technique of potentiostatic anodization (constant applied potential) for engineering PSi surface morphology. We demonstrate that under a constant applied potential, channel-like morphology, pyramids or well-ordered macropores are easily achieved through either increasing the processing time or adding a small amount of surfactant into the electrolyte. Our results provide better understanding of the mechanism underlying the formation of PSi and propose a practical solution for obtaining application-specific macrostructure of PSi.

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“…KOH etching has been known to expose Si (111) surface [30][31][32][33]. Indeed, such a sharpening protocol with KOH has been employed in the past to reveal 54.7°(111) surfaces at the top of Si micro-/nano-structures [34][35][36]. However, despite four equivalent (111) planes having the angle 54.7°to the (100) surface of Si wafer employed in this study, we have achieved the control of the angle in the range between 80°and 89.5°.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of arrays of tapered silicon micro-/nano-pillars by metal-assisted chemical etching and anisotropic wet etching

Yamada¹,

Yamada²,

Maki³

et al. 2018

Nanotechnology

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Fabrication of a 2D square lattice array of intentionally tapered micro-/nano-silicon pillars by metal-assisted chemical etching (MACE) of silicon wafers is reported. The pillars are square rod shaped with the cross-sections in the range 0.2 × 0.2-0.9 × 0.9 μm and heights 3-7 μm. The spacing between pillars in the 2D square lattice was controlled between 0.5 and 3.0 μm. While the pillars after MACE had the high aspect ratio ∼1:5, subsequent anisotropic wet etching in potassium hydroxide solution led to 80°-89.5° tapers with smooth sidewalls. The resulting taper angle showed the relation with geometry of pillar structures; the spacing 0.5-3.0 μm led to the tapering angle 89.5°-80° for 3 and 5 μm tall pillars but 7 μm tall pillars showed no dependency between the tapering angle and the inter-pillar spacing. Such an array of silicon tapered-rods with smooth sidewalls is expected to be applicable as a mold in nanoimprinting applications.

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A periodic array of silicon pillars fabricated by photoelectrochemical etching

Cited by 23 publications

References 27 publications

Photoelectrochemical hydrogen evolution of tapered silicon nanowires

Photoelectrochemical hydrogen evolution of tapered silicon nanowires

Effect of surfactant and etching time on p-type porous silicon formation through potentiostatic anodization

Fabrication of arrays of tapered silicon micro-/nano-pillars by metal-assisted chemical etching and anisotropic wet etching

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