Sulabha KulkarniIndian Institute of Science

Education & Research, Pune

Nano MaterialsSynthesis

Recent Trends in

Synthesis & Characterization Of

Multifunctional Materials(RTSCTMN-09)

22nd June 2009

Nano Materials,Characterization Techniques

Ref. Nanotechnology : Principles and Practices

By Sulabha K. Kulkarni

Capital Publishing Co.

7/28, Mahaveer Street, Ansari Road

Daryaganj, New Delhi -110002

Nano Materials,Characterization Techniques

Contents

Introduction to Quantum MechanicsStructure and BondingSynthesis of Nanomaterials (Physical Methods)Synthesis of Nanomaterials (Chemical Methods)Synthesis of Nanomaterials (Biological Methods)Analysis TechniquesProperties of NanomaterialsNanolithographySome Special NanomaterialsApplicationsPracticals

Nano Materials, Characterization Techniques

Lecture I• Which are the Nanomaterials are we looking for

• Methods of Synthesis

Lecture II• What kind of analysis is needed

• Available and commonly required analysis techniques

• Principles of some analysis techniques with

Illustrative examples

Nano Materials,Synthesis & Characterization Techniques

Materials with Size Dependent Properties

Properties of all materials are size dependent below ~ 100 nm!

(M. Faraday1857)!

CdS

CdSe

Ag

Au

Smith & Nie, Analyst 129 (2004) 672

Imaging using Quantum Dots of CdSe

Shape Dependence

Aspect ratio > 1

400 600 800 1000

0.25 ml AgNO3 720

0.3 ml AgNO3

780

BDAC/CTAB = 0.15M/0.2M

0.5 ml AgNO3

857

Inte

nsi

ty

Wavelength (nm)Photograph of gold nanospheres (left) and gold nanorods of increasing aspect ratio.

Photograph of gold nanospheres (left) and gold nanorods of increasing aspect ratio.

a 50 nm

300 400 500 600 700 8000.0

0.1

0.2

0.3

0.4

0.5

Ex

tin

cti

on

(ar

b.u

nit

s)

Wavelength (nm)

527 nm

Photonic Band Gap Materials

Kulkarni et al

Wonderful Carbon

Graphite Diamond

Fullerenes Carbon Naotubes

Latest is Graphene!

Look at the Nature Carefully

Micro + Nano StructureWaxy surface

Superhydrophobic !

Inspiration from the Nature

Understanding the behaviour of a water drop on a surface

water

hydrophobic surface

water

superhydrophobic

water

hydrophilic surface

Water loving-Water spreads almost completelye.g.glass

waterSuperhydrophilic surface

water

Water hating – A water bead is formede.g. teflon pan, lotus leaf

Wenzel Cassie-Baxter Both

Different Models to explain observed wettability

Roach et al. Soft Matter, 2008, 4, 224–240

Roach et al.

Soft Matter, 2008, 4, 224–240

Lithographyically Created Hydrophobic Surfaces (Si & SU8)

Hydrophobicity Tuning (S. K. Kulkarni)

Hydrophobic-Hydrophilic Transitions (TiO2)

X400 50mX400 50m

X400 50mX400 50m

0.5m

0.5m

5m

5m

5m

5m

5m

Thickness : 112 nm, 250 nm, 369 nm, 500 nm

RMS Roughness : 106 nm, 138 nm, 142 nm, 193 nm

Magnetron Sputter Deposited Thin Films

Super-hydrophobicity, CA ~ 176o

Anatase

5m5m

UV Induced Hydrophobicity to Hydrophilicity Transitionin TiO2 Thin Films

Feet of Lizard (Geko Effect)

Reminds you of Ghorpad used by Tanaji?

Novel Robos, stick tapes etc by mimicking a lizard

CdSe

TiO2

OTE

h

e

e h

h

h

CdSe

TiO2

OTE

h

e

e h

h

h

PtGlass

ITO

Aluminum

Redox or Hole Transport Layer

Met

al

SemiconductorNanocrystals

(a)

Glass

ITOPEDO

T

Aluminum

Active Polymer/Semiconductor Layer

(b) (c)

CdSe

TiO2

OTE

h

e

e h

h

h

CdSe

TiO2

OTE

h

e

e h

h

h

Pt

CdSe

TiO2

OTE

h

e

e h

h

h

CdSe

TiO2

OTE

h

e

e h

h

h

PtGlass

ITO

Aluminum

Redox or Hole Transport Layer

Met

al

SemiconductorNanocrystals

Glass

ITO

Aluminum

Redox or Hole Transport Layer

Met

al

SemiconductorNanocrystals

(a)

Glass

ITOPEDO

T

Aluminum

Active Polymer/Semiconductor Layer

(b)

Glass

ITOPEDO

T

Aluminum

Active Polymer/Semiconductor Layer

(b) (c)CdSe

TiO2

OTE

h

e

e h

h

h

CdSe

TiO2

OTE

h

e

e h

h

h

PtGlass

ITO

Aluminum

Redox or Hole Transport Layer

Met

al

SemiconductorNanocrystals

(a)

Glass

ITOPEDO

T

Aluminum

Active Polymer/Semiconductor Layer

(b) (c)

CdSe

TiO2

OTE

h

e

e h

h

h

CdSe

TiO2

OTE

h

e

e h

h

h

Pt

CdSe

TiO2

OTE

h

e

e h

h

h

CdSe

TiO2

OTE

h

e

e h

h

h

PtGlass

ITO

Aluminum

Redox or Hole Transport Layer

Met

al

SemiconductorNanocrystals

Glass

ITO

Aluminum

Redox or Hole Transport Layer

Met

al

SemiconductorNanocrystals

(a)

Glass

ITOPEDO

T

Aluminum

Active Polymer/Semiconductor Layer

(b)

Glass

ITOPEDO

T

Aluminum

Active Polymer/Semiconductor Layer

(b) (c)

CdSe

TiO2

OTE

h

e

e h

h

h

CdSe

TiO2

OTE

h

e

e h

h

h

PtElectrolyte

Polymer Polymer Solar CellSolar CellPolymer Polymer Solar CellSolar Cell

Quantum Dot Quantum Dot Sensitized Solar CellSensitized Solar CellQuantum Dot Quantum Dot Sensitized Solar CellSensitized Solar Cell

Metal Metal Junction Junction Solar CellSolar Cell

Metal Metal Junction Junction Solar CellSolar Cell

Solar Cells using Nanomaterials

By P. V. Kamat

Electronics

Spintronics

Photonics

Space Vehicles

Medical/Diagnostics

Sports/Toys

Energy

Display Panels

Food/Agriculture

Consumer Goods

Nano Materials,Characterization Techniques

Size Dependent Physico-Chemical Propertiesrange of materials with change of properties,

without changing chemical composition

Large Surface to Bulk Atoms Ratio ideal for composites, reacting systems, drug delievery,

energy storage etc

Assemblyorganization in biological systems occurs at nanoscale,

in nanoscience non-bio materials also assembled at nanoscle

Which are the Nanomaterials are we looking for

Bulk, Quantum Well, Quantum Wire and Quantum Dot

Jacak, Hawrylak, Wojs, Quantum Dots (1998)

Band Gap Engineering CdS, ZnS, CdSe, ZnSe, PbS, ZnO, MnSb, SnO2 etc

Fluorescent Particles ZnS (CdS):Mn, Cu, Pb, Pure Semiconductors

Pigments Fe2O3, CoAl2O4, ZnCo2O4, etc

Core-shell Particles SiO2@CdS, ZnS etc or Au,CdS,ZnS @SiO2 or PS

Fullerenes C60 , C70

Porous Materials Aerogels (SiO2, RF etc), Porous Silicon, MCM-41

Spintronics Diluted Magnetic Semiconductors &Multilayers

Self Assembly Ge/Si (111) 7x7, In/Si (111) 7x7

Q - Well Spectroscopy Al / Si (111) 7x7

Gallery of Engineered Materials (nm to m)

Nano Materials, Synthesis Techniques

Materials can be in the form of

Single particles (powder)

Colloids, in liquids

Thin Films, Multilayers, Nanowires, Nanorods, Nanotubes, Quantum Dots, etc etc

Bulk Materials can be Metals, Semiconductors, Insulators

Top Down Nanotechnology Approaches

Bottom Up

Needles Flowers

Rods Tetrapods Belts

Fe2O3 particles

SiO2@Ag/Au

ZnOCdSe

SnO2

CdS

Aerogel

Some Nano-Materials Synthesized in our Laboratory

AAO

Au

BiFeO3

Synthesis of Nanomaterials

Physical -MBE,Sputter,Laser,lithography

Chemical-Sol-gel, coprecipitation

Biological

Hybrid-CVD,MOCVD etc

Synthesis of Nanomaterials

Complicated Simple

Choice depends upon money and expertise available

Nano Materials,Synthesis Techniques

Synthesis

Physical Chemiclal Biological Hybrid

Colloids, sol-gel, L-B films, Inverse micelles

Using biomembranes, DNA, enzymes and micro organisms

Electrochemical,Chemical vapour deposition, Particle arresting in glass or zeolites or polymers,Micro emulsion-zeolite

Vapour depositionMechanical

Physical vapour deposition, Laser ablation, Sputter deposition, electric arc deposition, ion implantation

High enrgy ball milling, melt mixing

Nano Materials,Synthesis Techniques

Different milling machines

Fritsch planetary miller Medium -high energy

research miller (<250g)

What we have!

Tumbler mill Energy depends on diameter and speed of

drum Primarily used for large -scale industrial

applications

SPEX miller: High energy,

research -scale

~10cm 3

Attrition mill High energy

small -industry scale (<100kg)

Nano Materials,Synthesis Techniques

Vacuum pump

Laser beam

Target

Plume

Substrate

Time

Laser Ablation

Lithography

Eelectron Beam

Lithography

Electron Microscope for

Lithography

EBL for making

Devices

Bragg-Fresnel lens in silicon using EBL

Scanning Tunneling Microscope

Atoms on silicon surface

Ultra High Vacuum STM

Lithography using STM/AFM Probe

Atom Corrals

Eigler et al

Dip Pen Lithography

Mirkin et al

Techniques of Soft Lithography

Micromolding in Capillaries (MIMIC)

Micro Contact Printing (μCP)

Annu.Rev.Mater.Sci.28 1998) 153

J.Am.Chem.Soc. 118 (1996)5722

Patterning of Silica Particles Using Micro Contact Printing

Kulkarni et al

Advantages of Chemical MethodSimple

Inexpensive (less instrumentation)

Control of Concentrations, Doping etc

Low temperature Synthesis

Large Quantities

Charge Carriers and Spins,Independently Controlled

Variety of Sizes (nano to micro) & Shapes Control

Liquids, Powders or Thin Films

Self Assembly/Patterning Possible

Chemical Synthesis of Nanoparticles

Bawendi et al

substrate

Subphase

(1)

(2)

(3)

(4)

Compressed layer

(5)Re-compressed layer

Langmuir-Blodgett Deposition

head

tail

water

Hydrophobic

bic end

Hydrophilic end

H

C HH

C

C HH

C HH

C

O O

H

(b) inverse micelle

W/O emulsion

oil

water droplet

micelle(a)

O/W emulsion

water

oil droplet

Micellar emulsion

oil droplet

Water

micelle

Micelles / Inverse Micelles

Sol

Supercritical extraction

Aerogel

Sol fiberspowders

Xerogel film

heat

Gel

Evaporation of solvent

Xerogel

Ceramic Film

Dense glass/Ceramic

Dry, heat

Sol-Gel

Nano Materials,Synthesis Techniques

Bio-Nano

Use of micro-organisms like fungi, yeast, bacteria

Use of plant extracts or enzymes

Use of templates like DNA, membranes, viruses etc

Nano Materials,Synthesis Techniques

Self assembly of nanoparticles

CdS nanoparticles

(a)

COO-

COO-

COO-

COO-

COO-

AlOxide Layer

Adsorption of silver colloidal particles

COO

Al

COO

S

COO

S

COO

S

COO

S S

(c)

COO

Al

COO

S

COO

S

COO

S

COO

S S

(b)

S

S

MetalS

S

S

S

S

S

S

S

S

S

S

S

S

S

S

S

S

S

MetalS

S

S

S

S

S

S

S

S

S

S

S

S

S

S

S

Nano Materials, SynthesisTechniques

(d)

(c)(e)

(a)

(b)

S-layer

Gold NP Substrate

Lipid

Use of S-Layers in Nanoparticles Synthesis

Nano Materials, Synthesis Techniques

Metal ion

Channel

Cavity

Protein shell6 nm 12 nm

Monomer subunit

(a) (b)

Ferritin for the Synthesis of Nanoparticles