2 Nanowire Synthesis

2 Nanowire Synthesis - Nanowire Synthesis Lecture-2 Reading...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Nanowire Synthesis Lecture-2 Reading uploaded: -Younan Xia and Peidong Yang, Advanced Materials 15 , 353 (2003). Definition of Nanowires - Critical dimension: Diameter <1000 nm - Aspect ratio (length to diameter). “nanorods” for small aspect ratio The borderline between nanowires and nanorods is very vague. - Materials: semiconductor, metal, oxides, insulators. Other names: Quantum wires: showing quantum properties. Molecular wires: with well defined molecular diameter dimension. Synthesis Strategies • • • • • • Precursors Nanocrystals Nanowires 1)Anisotropic crystal structures 2)Templates 3)Vapor-liquid-solid (VLS) and solution-liquid-solid growth (SLS) How to break the growth symmetry? Anisotropic Crystal Structures Se Nanowires - Selenium crystal is trigonal, consisting of Se helical chains in hexagonal packing. - Intrachain: covalent bond; Interchain: van der Waals. 4s 2 4p 4 Eight-electron rule: One Se atom bonded with two neighbors. Anisotropic Crystal Structures Se Nanowires (Younan Xia) The anisotropic structure method only limits to few materials. Template Methods: 1)On Solid surface 2)Channels in Porous materials 3) Micelles and reversed micelles 4) Existing nanowires and nanotubes Template Method-1 Template on solid substrates Shadow evaporation V-groove reconstruction Cleaved-edge overgrowth Step-edge decoration...
View Full Document

This note was uploaded on 06/05/2010 for the course MATSCI 316 taught by Professor Cui,y during the Winter '08 term at Stanford.

Page1 / 30

2 Nanowire Synthesis - Nanowire Synthesis Lecture-2 Reading...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online