Analysis concept of gaseous or liquid media using porous silicon multilayers with optical sensing is presented. The sensor consists of optical filter with λ/4 layers, fabricated by electrochemical etching in HF/ethanol. The optical system is tested with ampicillin and shows a linear dependence with increasing ampicillin concentration. For general sensing applications the influences of porosity ...

III-nitride membranes offer promising perspectives and improved device designs in photonics, electronics, optomechanics. However, the removal of growth substrate often leads to a rough membrane surface, which increases scattering losses optical devices. In this work, we demonstrate with etched surface roughness comparable that as-grown epitaxial material, accomplished by implementation properly...

Size-controlled synthesis of luminescent quantum dots of MoS2 (≤2 layers) with narrow size distribution, ranging from 2.5 to 6 nm, from their bulk material using a unique electrochemical etching of bulk MoS2 is demonstrated. Excitation-dependent photoluminescence emission is observed in the MoS2 QDs. "As-synthesized" MoS2 QDs also exhibit excellent electrocatalytic activity towards hydrogen evo...

Novel anodic aluminium oxide (AAO) films and hollow nanostructures were synthesized via a simple electrochemical and chemical etching route; fluctuating nanotube growth inside AAO film fabricated under ultra-high voltage was considered to be the main reason for the formation of such new structures.

The defect structure in relaxed (100) InGaAs/GaAs heteroepitaxial systems grown by molecular beam epitaxy is studied by selective electrochemical (anodic) etching. By incremental layer removal, we map the depth profile of the dislocation density. The density of dislocations is inversely proportional to the layer thickness and increases with misfit. The results are compared to theoretical models.

A scanning electrochemical microscope (SECM) was used as an analytical tool to study the etching of GaAs surfaces. Hole injection from several eledrogenerated oxidants to n-type, p-type, and undoped GaAs was examined by the feedback mode of the SECM. Assignment of the process as a hole injection from the oxidized form of the redox couple into the valence band and assignment of the energy of the...

Fabrication of microporous structures for the anode of a thin film solid oxide fuel cell (SOFC(s)) using controlled etching process has led us to increased power density and increased cell robustness. Micropores were etched in the nickel anode by both wet and electrochemical etching processes. The samples etched electrochemically showed incomplete etching of the nickel leaving linked nickel isl...

This work reports the coating of porous silicon (PS) with LaF3 and its influence on the photoluminescence (PL) property of PS. PS samples, prepared by electrochemical etching in a solution of HF and ethanol, were coated with e-beam evaporated-LaF3 of different thicknesses. It was observed that the thin LaF3 layer on PS led to a good enhancement of PL yield of PS. But with the increasing thickne...

Electrochemical etching of semiconductors, beside technical applications, provides an interesting experimental setup for self-organized structure formation capable of regular, diameter-modulated, and branching pores. The underlying dynamical processes governing current transfer and structure formation are described by the Current-Burst-Model: all dissolution processes are assumed to occur inhom...