14 The development and status of what is commonly called the Gerischer mechanism of silicon etching in 15 fluoride solutions is reviewed. The two most widely used and studied wet etchants of silicon are F 16 and OH . Their mechanisms of atom removal share many things in common; in particular, chemical pas17 sivation by a hydrogen-terminated surface plays an important role in both. Crucially, ho...

Quite recently, ion-track membranes of poly(vinylidene fluoride) (PVDF) have attracted a renewed interest for their applications to next-generation electrochemical devices such as fuel cells [1,2]. In order to produce tracketched pores in PVDF films, several kinds of etching solutions were previously employed. In most cases [3], a highly concentrated aqueous KOH solution with a KMnO4 additive w...

in this paper, the electrochemical behaviour of passive films formed on aisi 321 stainless steel (aisi 321)immersed in 0.1 m naoh + 0.1 m koh solution was evaluated by different electrochemical techniques. forthis purpose, passive films were formed at open circuit potential for 1 to 12 hours and then electrochemicalmeasurements were done. the polarization curves suggested that aisi 321 showed e...

High quality graphene films can be fabricated by chemical vapor deposition (CVD) using Ni and Cu as catalytic substrates. Such a synthesis procedure always requires a subsequent transfer process to be performed in order to eliminate the metallic substrate and transfer the graphene onto the desired surface. We show here that such a transfer process causes significant contamination of the graphen...

We report the effect of chemical etching of p-GaN using molten KOH:NaOH solution on leakage currents, light output power, and electrostatic discharge ESD characteristics of GaN light-emitting diodes LEDs . Photoluminescence and capacitance–voltage measurement indicated that a deep donor–acceptor pair DDAP was densely concentrated near the p-GaN surface region 18 nm and the defects were effectiv...

: Analysis methods for electrochemical etching baths consisting of various concentrations of hydrofluoric acid (HF) and an additional organic surface wetting agent are presented. These electrolytes are used for the formation of meso- and macroporous silicon. Monitoring the etching bath composition requires at least one method each for the determination of the HF concentration and the organic co...

In this paper, we study the electrochemical anodization of n-type heavily doped 4 H-SiC wafers in a HF-based electrolyte without any UV light assistance. We present, in particular, the differences observed between the etching of Si and C faces. In the case of the Si face, the resulting material is mesoporous (diameters in the range of 5 to 50 nm) with an increase of the 'chevron shaped' pore de...

We demonstrate silicon-based phosphor materials which exhibit bright photoluminescence from near-infra-red to green. The colloidal composites which are composed of silicon quantum dots (SiQDs) attached on micro-size silicon particles are synthesized by electrochemical etching of silicon wafers and then dispersed in ethanol. Subsequently, isotropic etching by HF/HNO3 mixture controls the size so...