PH driven addressing of silicon nanowires onto Si3N4/SiO2 micro-patterned surfaces. (8th June 2016)

• Record Type: Journal Article
• Authors: Cloarec, Jean-Pierre; Chevalier, Céline; Genest, Jonathan; Beauvais, Jacques; Chamas, Hassan; Chevolot, Yann; Baron, Thierry; Souifi, Abdelkader
• Is Part Of: Nanotechnology. Volume 27:Number 29(2016)
• Publication Date: 2016-06-08
• Subjects: localization -- patterned surfaces -- silicon -- nanowires -- pH -- electrostatic forces -- DLVO theory; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/0957-4484/27/29/295602
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: pH was used as the main driving parameter for specifically immobilizing silicon nanowires onto Si3 N4 microsquares at the surface of a SiO2 substrate. Different pH values of the coating aqueous solution enabled to experimentally distribute nanowires between silicon nitride and silicon dioxide: at pH 3 nanowires were mainly anchored on Si3 N4 ; they were evenly distributed between SiO2 and Si3 N4 at pH 2.8; and they were mainly anchored on SiO2 at pH 2. A theoretical model based on DLVO theory and surface protonation/deprotonation equilibria was used to study how, in adequate pH conditions, Si nanowires could be anchored onto specific regions of a patterned Si3 N4 /SiO2 surface. Instead of using capillary forces, or hydrophilic/hydrophobic contrast between the two types of materials, the specificity of immobilization could rely on surface electric charge contrasts between Si3 N4 and SiO2 . This simple and generic method could be used for addressing a large diversity of nano-objects onto patterned substrates.