Properties of silver/porous-silicon nanocomposite powders prepared by metal assisted electroless chemical etching

Abstract

Defect mediated ferromagnetism in Ni-doped ZnO nanocrystals evidenced by positron annihilation spectroscopy J. Appl. Phys. 112, 083905 (2012) Formation of SiGe nanocrystals embedded in Al2O3 for the application of write-once-read-many-times memory Appl. Phys. Lett. 101, 163503 (2012) Local structural disorder in Zn0.9Co0.1O nanocrystals studied using neutron total scattering analysis J. Appl. Phys. 112, 073523 (2012) Impact of induced bandgaps on sub-Poissonian shot noise in graphene armchair-edge nanoribbonsWe demonstrate that silver/porous-Si nanocomposite powders are obtained by etching Si powders with metal assisted electroless chemical reaction in an aqueous solution of AgNO 3 and HF. From x-ray photoelectron spectroscopy and scanning electron microscope measurements, metal layer consisting of nanometer-sized Ag particles and their aggregates is formed on each Si powder surface. Immoderate etching at higher concentrations of AgNO 3 results in the decrease in Si volume and increase in Ag layer thickness. Dips are observed in reflectance spectra of the nanocomposite powders at ϳ400 nm. By comparing the experimental spectra with theoretically calculated ones, these dips are found to arise from the optical absorption due to the roughness-assisted surface plasmon excitation and to be dependent on the size of the Ag nanostructure. The nanocomposite powders show weaker photoluminescence intensity than that of conventionally stain-etched porous Si powders, however, their photostability is improved. The improvement of the photostability is considered to be due to the existence of surface Si-O and Si-Ag bonds.

Optical properties of black silicon prepared by wet etching

“…In the mechanism, the metallic nuclei behave as a cathode to mediate the reduction of H 2 O 2 and consequent hole injection and their surrounding area acts as an anode, resulting in the etching of the surrounding area [25] as revealed in Fig. 4.…”

Optical Properties of Porous Silicon*

“…This procedure produced dispersions of photoluminescent Si nanoparticles in the size range of 3-6 nm after sonication of the grains in iso-propanol. Nakamura et al produced both Ag/por-Si (Nakamura et al 2010) and Pt/por-Si (Nakamura et al 2011) composite powders from metallurgical grade Si powder. The powder was added to the 18% HF, followed by AgNO 3 .…”

Facile synthesis of porous copper nanobelts and their catalytic performance

“…The design and synthesis of porous metal nanostructures or architectures have been developed into an increasingly important topic in recent years as driven by their widespread applications in advanced catalysis, biofiltration, sensing, electrochemistry, fuel cells, and so on [1][2][3][4][5][6][7][8][9][10][11]. Current strategies for fabricating porous metal nanostructures mainly include dealloying, sacrificial template and self-assembly avenues.…”