SHINE: S eattle’s H ub for I ndustry-driven N anotechnology E ducation North Seattle College Nanotechnology Fabrication

Seattle’s Hub for Industry-Driven Nanotechnology Education Nanomaterial Fabrication A nanomaterial is a structure which is smaller than 100 nm in at least one dimension. 0-D Nanoparticles 1-D Nanowires or nanotubes 2-D Thin films 3-D Porous structures

Seattle’s Hub for Industry-Driven Nanotechnology Education Types of fabrication 3 Top DownBottom Up Chemistry! Crystal Growth 0-D particles 1-D particles 2-D films Milling Large size distribution No control of shape Impurities Lithography

Seattle’s Hub for Industry-Driven Nanotechnology Education Nucleation and growth NP’s from homogenous solution Source: Nanostructures & Nanomaterials, Cao, G. Fig. 3.2 As r  E surface  E surface α r 2 As r  E volume  E surface α r 3 r* = critical nucleus size

Seattle’s Hub for Industry-Driven Nanotechnology Education 0-D Nanoparticle Synthesis Example: Reduction of chlorauric acid (HAuCl 4 ) with sodium citrate  Gold NPs 5

Seattle’s Hub for Industry-Driven Nanotechnology Education 1-D Nanostructures Nanowhiskers and fibers Nanorods and nanobelts Nanowires Carbon Nanotubes 4 : 16 : 112 : 1 36 : 1 Aspect ratio = length ÷ diameter

Seattle’s Hub for Industry-Driven Nanotechnology Education 1-D Nanostructures Bottom up: Anisotropic spontaneous growth Template directed Top Down: Laser ablation synthesis of carbon nanotubes (CNTs)

Seattle’s Hub for Industry-Driven Nanotechnology Education Anisotropic Growth Surfactants can bind to certain facets of a crystal and encourage anisotropic growth 8

Seattle’s Hub for Industry-Driven Nanotechnology Education Template Based Synthesis 9 Cross section of nanowires in template

Seattle’s Hub for Industry-Driven Nanotechnology Education 10 Synthesis of Carbon Nanotubes Laser ablation (vaporizing graphite with a laser) Plasma arcing of graphite or coal Combustion synthesis –Burn hydrocarbon at low pressure

Seattle’s Hub for Industry-Driven Nanotechnology Education 2D Nanostructures Thin films – Thickness less than 100 nm Vapor Deposition Thermal Evaporation Sputtering Chemical Vapor Deposition (CVD) Solution Deposition Self-assembly Electroplating Spin Coating

Seattle’s Hub for Industry-Driven Nanotechnology Education Thermal Evaporation 1. Vacuum (10 -4 – Torr) 2. Source material is heated and evaporates 3. Source material deposits on substrate Control concentration of growth species in vapor Thickness measured in situ Angstroms to 100’s nm thick layers

Seattle’s Hub for Industry-Driven Nanotechnology Education Sputtering 1.Rough Vacuum (10’s of mTorr) with a constant stream of gas 2.High voltage forms plasma ex: Ar gas  Ar + + e - 3.Plasma (Ar + ) accelerated towards target 4.Ar + hits target, neutral target atoms (Au) are ejected 5.Ejected atoms (Au) deposit on substrate

Seattle’s Hub for Industry-Driven Nanotechnology Education Chemical Vapor Deposition (CVD) 1.Rough Vacuum (10’s of mTorr) 2.Reactive gas added 3.Chemical reaction in gas phase or on surface

Seattle’s Hub for Industry-Driven Nanotechnology Education Image References 15 Slide 4 Guoshong, Cao. "Nanostructures and nanomaterials." (2004). Fig. 3.2 Slide 5 Gold Nanoparticle Synthesis. UWMRSEC. [Online Image] 22 May, Slide 8 Gold Nanoparticle Growth. Chalmers Research Group. [Online Image] 29 May, Slide 9 Artin Petrossians, John J. Whalen III, James D. Weiland and Florian Mansfeld (2013). Nanotechnology for Packaging, Advances in Micro/Nano Electromechanical Systems and Fabrication Technologies, Assistant Professor Kenichi Takahata (Ed.), InTech, DOI: / Available from:

Seattle’s Hub for Industry-Driven Nanotechnology Education Image References 16 Slide 10 Carbon Nanotube. UC Davis ChemWiki. [Online Image]. 29 May Arc Discharge. Somnath2. [Online Image] 29 May Slide 12 Thermal Evaporation. [Online Image] 29 May Slide 13 Sputtering. Physics StackExchange. [Online Image] 29 May Slide 14 MOCVD. Crystalgrower. [Oniline Image] 29 May 2016.

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