Inherent formation of porous p-type Si nanowires using palladium-assisted chemical etching

• Published in: Applied surface science 2017-01, Vol.392, p.498-502
• Main Authors: Chen, Jun-Ming, Chen, Chia-Yuan, Wong, C.P., Chen, Chia-Yun
• Format: Article
• Language: English
• Subjects: Arrays; Band diagram; Chemical etching; Etching; Nanowires; Palladium; Palladium nanoparticles; Photoluminescence; Porous silicon; Silicon; Silicon substrates
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2016.09.048

•Porous Si nanowire arrays were synthesized from lightly p-doped Si substrates using a Pd-assisted chemical etching at room temperature.•Detailed investigations on the Pd depositions and correlated etching mechanism in the presence of H2O2/HF reactants were performed.•The synthesized porous Si nanowires demonstrated the remarkable photoluminescent intensity at the center wavelength of 580nm. Porous silicon (Si) nanowire arrays were directly fabricated from lightly p-doped Si substrates using a palladium (Pd)-assisted chemical etching at room temperature. The mechanistic studies indicated that anodic dissolution of Si was established by the accumulated positive charges at Pd/Si schottky interfaces in the presence of H2O2 oxidants. In addition to the primary etching direction vertically to the substrate planes, the additional sidewall etching was stimulated by the separated Pd nanoparticles during reaction that constitutes the porous features covering on the nanowires surfaces thoroughly. These combined effects lead to the distinct etching characteristics and remarkable photoluminescent properties of resulted nanostructures.