Multiple etching pathways for the formation of porous Si nanostructures are visualized with the addition of ethylene glycol in metal-assisted chemical etching. The monotonic transition from solid to porous morphologies of Si nanostructures along with remarkable photoluminescence (PL) emission efficiency and distinct wetting phenomena can be observed.

Actual dimension control of silicon (Si) nanowire arrays was conducted using metal-assisted chemical etching on Si patterned by electron beam lithography. The appearance of nanogaps at the edge of each nanowire provides the diffusion pathways of reactants for Si dissolution, predominantly causing distinct etching rates that depend upon the spacings of nanogaps.

The chemical transformations taking place during many of the reactions Si surface have been well documented, but in situ dynamics remain largely unexplored even for widely used electrochemical processes such as metal-assisted etching (MACE). In this work, we design both n- and p-type photoconductors covered with silver nanoparticles to demonstrate photoconductors’ sensitivity MACE process their...

A simple method for the fabrication of porous silicon (Si) by metal-assisted etching was developed using gold nanoparticles as catalytic sites. The etching masks were prepared by spin-coating of colloidal gold nanoparticles onto Si. An appropriate functionalization of the gold nanoparticle surface prior to the deposition step enabled the formation of quasi-hexagonally ordered arrays by self-ass...

Periodic high aspect ratio GaAs nanopillars with widths in the range of 500-1000 nm are produced by metal-assisted chemical etching (MacEtch) using n-type (100) GaAs substrates and Au catalyst films patterned with soft lithography. Depending on the etchant concentration and etching temperature, GaAs nanowires with either vertical or undulating sidewalls are formed with an etch rate of 1-2 μm/mi...

We demonstrate GaAs pillar array-based light emitting diodes (LEDs) with axial p-in junctions fabricated using a room-temperature metal-assisted chemical etching (MacEtch) method. Variations in vertical etch rates for all three doping types of GaAs are investigated as a function of etching temperature, oxidant/acid concentration ratio, and dilution of the etching solution. Control over nanopill...

We propose the metal-assisted chemical etching of Ge surfaces in water mediated by dissolved oxygen molecules (O2). First, we demonstrate that Ge surfaces around deposited metallic particles (Ag and Pt) are preferentially etched in water. When a Ge(100) surface is used, most etch pits are in the shape of inverted pyramids. The mechanism of this anisotropic etching is proposed to be the enhanced...