it)ty (arb. uniIntensit

(1)

Growth of Single-Walled Carbon Nanotubes on Surface with Controlled Structures

on Surface with Controlled Structures

Prof. Jin ZHANG

Center for nanochemistry

College of Chemistry and Molecular Engineering P ki U i it B iji 100871 P R CHINA Peking University, Beijing 100871, P. R. CHINA

Email: [email protected]

The University of Tokyo, 1^st Nov, 2010, Tokyo

(2)

Introduction of Single-walled Carbon Nanotubes

C

C_h_h = n= naa₁₁ + m+ maa₂₂ (n,m)(n,m)

Zigzag Nanotube Armchair Nanotube

 / ) (

3a n² m² nm ¹^/² d_t  _C__C  









 ^ 

m n

m 2 tan ¹ 3



tor semiconduc

metal 1

3 3





 

 p

m p n

Nanotube transistor Nanotube RAM Flat panel display Nanotube interconnect

N o ube s s o N o ube p e d sp y Na otube te co ect

(3)

A Scalable CVD Synthesis of High-Purity SWNTs with

P M O S t M t i l

Porous MgO as Support Materials

2000 2500

it)

SEM

TEM

1500

ty (arb. uni

500 1000

Intensit

400 800 1200 1600

0

Raman shift (cm^-1)

Support：MgO；Catalysts：Fe；Carbon Source：CH₄

J. Zhang et. al. , J Mater Chem, 12(4): 1179-1183, 2002； Carbon, 40(12): 2282-2284, 2002；Carbon, 40(14): 2693-2698, 2002

(4)

Surface Growth of SWNTs by CVD

Catalyst

Growth Process:

C SWNTs

Nanoparticley

C

SWNTs

Substrate Substrate Substrate

Q ti

Questions:

1. Growing SWNTs on Surface Directly with Controlled Density, Position and Orientation

and Orientation

2. Growing SWNTs on Surface with Controlled Diameter

3 Growing SWNTs on Surface with Controlled Metallic and Semi 3. Growing SWNTs on Surface with Controlled Metallic and Semi-

conducting Properties

4. Growing SWNTs on Surface with Controlled Chirality 4. Growing SWNTs on Surface with Controlled Chirality

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Controlled CVD Growth of SWNTs on Surface

a

The first time The second time

2m

J Ph Ch B 2005 109 10946

J Ph Ch B 2004 108 12665 J. Phys. Chem. B, 2005, 109, 10946 J Ph Ch C 2008 112 8319 J. Phys. Chem. B. 2004, 108, 12665

84°

J. Phys. Chem. C, 2008, 112, 8319

J. Am. Chem. Soc. 2005, 127, 8268.

J. Phys. Chem. B, 109 (2005) 2657-2665 J. Am. Chem. Soc. 2005,127,17156

130°

J. Phys. Chem. B, 109 (2005) 2657 2665

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Challenges for the Application of Carbon Nanotubes in Future Device

1）How to achieve a structure-controlled synthesis of nanotubes ?

 Diameter

 Lattice geometry (armchair zigzag chirality)

 Lattice geometry (armchair, zigzag, chirality)

 Semiconduting or Metallic Nanotubes 2）How to fabricate a desired device structure ?

 Controlled surface growth M i l ti

 Manipulation

3）What architecture should the nanotube device have ?

4）How to integrate trillions of individual nanotube devices ?

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Our strategy towards SWNTs-based CMOS chips

A i l B d St t E i i

Photocatalytic cutting

• Direct CVD growth

—— Axial Band Structure Engineering

Substrate-induced local deformation Photocatalytic cutting

Direct CVD growth

• Transfer-printing

local deformation

Organic/inorganic

d l ti l Cl i h

modulating layer

Diameter-tuning growth

m/s sorting or chemical conversion

Cloning growth

conversion Chinese patent： ZL 2006 1 0113214.5

ZL 2006 1 0113212.6

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Catalytic CVD Growth of SWNTs Arrays on Surface

a-plane

Lattice Directed Growth Mode

Carbon source : Methane, ethanol, etc Substrate: Sapphire, quartz, SiO₂/Si, etc

Gas Flow Directed Growth Mode

etc

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Lattice Directed Growth vs. Gas Flow Directed Growth

on SiO₂/Si ♦ Tube diameter: 1-2 nm

♦ Length：> 5 cm

♦ Spacing: 1 50 m

rected wth

♦ Spacing: 1-50 m flow dir VD growGas CV

 Diameter：ca. 1 nm on sapphire

nted th

 Length：ca. 1 mm

 Spacing：~0.2 m pp

ice orien VD growt

1.4mm

Latti CV

(10)

Outline



Controlling Morphology of SWNTs on Surfaces

Surfaces



Direct Growth of Semiconducting SWNT Arrays

C C



^T ⁱ ^Di ^t f SWNT b ^C

C



Tuning Diameters of SWNTs by Temperature



Cap-engineering for SWNTs

Growth with Controlled Chiralities

(11)

Controlling Morphology of SWNTs on

Surfaces by Combing the Two Growth Modes

(12)

Growth of serpentine SWNTs

(a) (c)

Substrate

(b)

Quartz or Quartz or

sapphire Certain lattice direction

♦The spacing between two parallel sections is mainly determined by the

♦The spacing between two parallel sections is mainly determined by the landing rate of the ultralong SWNT.

♦The landing rate can be controlled by cooling rate.

Therefore, the folding density of serpentine SWNTs can be controlled by cooling rate

cooling rate.

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Serpentine SWNTs grown at different cooling rates

r

10 min 20 min 30 min

r u u

r u

25 25

25 25 m 25 m

25 m

40 min 50 min

r r

40 min 50 min

r u

r

25 m u 25 m r

u

T from 975^oC to 775 ^oC.

The slower the cooling speed, the higher the tube folding density.

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High Performance SWNT-FET with Identical Chirality

10  m 19 CNT

10  m

-1 0x10^-4 0.0

(A)

4 CNT

Pd electrode, 800nm SiO₂

gate dielectric ^-2.0x10

-4

-1.0x10

V_g= -20V

I ds(

19 CNT

2.5  m

4 CNT ^-2 V_ds^-1 (V) ⁰

3.0x10^-4 V_ds= 0.5V

10^-6 10^-4

s(A)

19 CNT 4 CNT

2.5  m

1.0x10^-4 2.0x10^-4

Ids(A)

-20 0 20

10^-8

V_ds= 0.1V

V (V)

I ds 4 CNT

0 6 12 18

0.0

Number of tubes V_g (V)

J. Zhang, et. al., Adv. Mater. 2009, 21, 4158-4162. (Inter Front Cover Paper).

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The highest density we have achieved

(a) (b)

High density High density of SWNTs make it 1×1μm²

(spacing of ~50 nm)

possible to observed

i k

10⁵

LF 2RBM

G RBM=290

a.u.) ^{G RBM}

various weak second-order Raman from

10⁴

NC1 NC2

iTOLA LF

**

*

**

* ^D

2RBM

IMF

M

G'(2D)

sity (a ^G+RBM Raman from

SWNTs.

100 600 1100 1600 2100 2600 3100 10³

* ** * ^NC3 _2G

Intens

100 600 1100 1600 2100 2600 3100

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Grow SWNT cross-bars in one batch

aa- plane

Lattice Directed Growth Mechanism

Gas Flow Directed Growth Mechanism

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Interaction between Cu, Fe Catlysts and Quartz Surface

a) and b) illustrate the interaction between Cu, Fe nanoparticles and surface of quartz, the red balls represent oxygen atoms. c) and d) High-magnification SEM image of the lattice assisted SWNTs catalyzed by Cu and Fe. e) and f) Results of gas flow directed growth of carbon nanotubes where Cu and Fe are used as catalysts

ti l respectively.

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SWNT Cross-bars and Its Potential Application

Low

temperature favors for lattice oriented

growth mode and high T for gas flow directed

growth mode.

Wi h With a moderate 930-950^oC, crossbar can crossbar can be grown.

J. Zhang et. al., J. Phys. Chem. C. 2009, 113, 5341-5344 (cover)

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Direct Growth of Semiconducting SWNT

Arrays by UV Irradiation Assistance CVD

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Separation of s-SWNTS and m-SWNTs after Growth

Ion-exchange chromatography density gradient ultracentrifugation

Functionalization

A Hirsch Angew Chem Int Ed 2002 M S Arnold Nature Nanotech 2006 M Zheng Nature Mater 2003

A. Hirsch, Angew. Chem. Int. Ed. , 2002 M. S. Arnold, Nature Nanotech. , 2006 M. Zheng, Nature Mater., 2003

alternating current dielectrophoresis gas-phase plasma hydrocarbonation Laser Irradiation

R. Krupke. Science, 2003 H. J. Dai. Science, 2006 H. J. Huang, J. Phys. Chem. B, 2006 R. Krupke. Science, 2003 H. J. Dai. Science, 2006 H. J. Huang, J. Phys. Chem. B, 2006

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Why s-SWNTS and m-SWNTs can be Separated

When a reactant comes near the SWNT, the electron can transfer from the metallic SWNT, but cannot transfer from the semiconducting SWNT. After that, the metallic SWNT can be damaged and the semiconducting SWN still survived

still survived .

J. Zhang, et. al., J. Phys. Chem. C 112, 3849, (2008)

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Setup of Our Home-Made CVD System

Li h Light

Source UV Light Filter

Furnace Furnace

Quartz Tube UV Light

Substrate

Furnace

(23)

SEM images of SWNTs arrays under different irradiation time 80mW/cm²

15min 80mW/cm²

10min

No Irradiation

100 m 100

80mW/cm² 20 i

80mW/cm² 30 i

270mW/cm² 30 i

100um 100um

100um

20min 30min 30min

100um 100um

40um

When UV beam acted on the substrate, the density of the SWNT array decreased obviously. From above, the shorter the irradiation time, the longer and denser the SWNTs were. If we continued increasing the irradiation time or the irradiation intensity SWNTs would become shorter and shorter and disappeared eventually

irradiation intensity, SWNTs would become shorter and shorter, and disappeared eventually

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UV Beam

(A) (B) (C)

Furnace Furnace

Shield

( ) ( )

100um 100um

Furnace

Part B Part A

M S S

514 5 nm

S

632 8 nm

(D) (E) (F)

514.5 nm 514.5 nm 632.8 nm

Raman Shift (cm^-1) Raman Shift (cm^-1) Raman Shift (cm^-1)

(A) Sketch map of the comparison experiment for SWNT growth with and without UV irradiation. (B)/(C) SEM image of the growth result without/with UV irradiation. (D) Raman spectrum for part B with 514.5 nm excitation. (E)/(F) Raman spectrum for part A with 514.5/632.8 nm excitation. The metallic SWNTs signals were collected in the yellow rectangle while the semiconducting SWNTs signals were collected in the blue rectangle separately for all the three spectra.

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25 C A

100um

10 15 20 A

B

V_ds = 100 mV, L = 5.6 um, d_SiO2 = 800 nm

0 5 10 B

10um -6 -4 -2 0 2 4 6

V_g (V) 0

Raman spectra demonstrated an amazing result that almost 100%g SWNTs were semiconducting.

Electrical measurement data showed that 21 out of 22 SWNTs (~95%) were semiconducting.

J. Zhang et al., J. Am. Chem. Soc., 2009, 131, 14642-14643

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C C C C

Tuning Diameters of SWNTs by

Temperature-oscillation CVD growth

Temperature oscillation CVD growth

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Controlling Diameters of SWNTs

By Catalyst Particle By Carbon Feeding

J. Phys. Chem. B. 2002,106, 2429-2433 J. Phys. Chem. B. 2006,110,20254-20257

(28)

Our Approach: Tune the Diameter of SWNTs by T

Temperature

T t P

Temperature Program

940 ature /o C

0 40 80 120 160

900 920

Tempera

Time /min Time /min

C C

C

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Micro-Resonance Raman Spectrum of Individual SWNTs

E_laser_laser

1μm SWNT^SWNT

Micro

Micro--Raman spectroscopyRaman spectroscopy ResonanceResonance condition: Econdition: E_laser_laser==E_ii

4 0 0 0 4 5 0 0 5 0 0 0

5 5 0 0 G-mode

Radial Breathing Mode ^(RBM)

632.8nm

1 0 0 0 1 5 0 0 2 0 0 0 2 5 0 0 3 0 0 0 3 5 0 0

Intensity Disorder-

induced Line (D-

ω＝(d_t-β)/ α

0 2 0 0 4 0 0 1 0 0 0 1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 - 5 0 0

0 5 0 0 1 0 0 0

R a m a n s h i f t ( c m - 1 )

induced Line (D

line) (m,n)

A power tool for both the atomic and electronic structure of SWNT !

R a m a n s h i f t ( c m 1 )

(30)

Constant-temperature CVD

a c

1 m

) b m) ₂ d

100  m

138

shift (cm-1

b

Height (nm

0

0 3000 6000

132

Distance along the tube (m)

Raman s H

Distance (µm)

0 1

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SWNTs Grown by one Time Temperature O ill t d CVD (F 900^oC t 950^oC)

T₂

T

Oscillated CVD (From 900^oC to 950^oC)

T₁

nsity

T₂

nsity

-100 0 100 200

Distance alone the tube (m) Inten Inten

-1 t (cm) 150 _（_T

1 < T₂）

1560 1600 120 160

T₁ T₁

man shift 140

T₂ T₁

145

1560 1600 120 160

S S

-100 0 100 200

Ram

Distance alone the tube (m)

135

S₁ S₂

Semiconducting－

Semiconducting Nanojunction Semiconducting Nanojunction

(32)

SWNTs Grown by one Time Temperature O ill t d CVD (F 950^oC t 900^oC)

Oscillated CVD (From 950^oC to 900^oC)

ty

T₂

tyT₁ T₂

Intensit

T

Intensit

T₂

-100 0 100

150 200 250

T₁ T₁

1500 1600 240

(cm-1 )

（T₁ > T₂）

man shift ^T²^T¹

210

-100 0 100

Ram 180

M₁ M₂

Metallic－Metallic Nanojunction

Distance alone the tube (m) j

(33)

Controlled Thinning of SWNTs via Temperature St U

Step-Up

(c) (d) (e) (f)

2 04±0 06 nm

1 m

1 86±0 05 nm

1 m

1 76±0 03 nm

1 m

1 32±0 04 nm

1 m

2.04±0.06 nm 1.86±0.05 nm 1.76±0.03 nm 1.32±0.04 nm

(34)

Controlled Thickening of SWNTs via Temperature Step Down

Step-Down

(c) (d) (e) (f)

1 34±0 04 nm 1 45±0 03 nm 1 69±0 04 nm 1 98±0 05 nm

1 m 1 m 1 m 1 m

1.34±0.04 nm 1.45±0.03 nm 1.69±0.04 nm 1.98±0.05 nm

(35)

Tube Diameter from Wide to Narrow Distribution

Narrowing the di t ib ti f t b distribution of tube

diameters by sequential temperature step-up or step-down

25

bes ₂₀

25

bes

c) 4.0 mm site

30 35 40

f tube

b) 2.0 mm site a) 1.0 mm site

10 15 20

mber of tub

10 15 20

mber of tub

10 15 20 25 30

umber of

0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 0

5

di t ( )

num

0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 0

num 5

di t ( )

0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 0

5

n 10

di t ( )

diameter (nm) diameter (nm) diameter (nm)

J. Zhang et. al., J. Phys. Chem. C, 2009, 113(30),13051-13059

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Multiple Intratube Nanojunctions by Repeating Temp. Oscillation

Six intramolecular junctions were induced by three temperature oscillations between 950^oC and 880^oC during CVD. (A) shows the scheme of temperature oscillation with time; (B) is an SEM image of several parallel ultralong SWNTs grown during the temperature oscillation; (C) shows Raman RBM peak

positions along a SWNT each peak corresponds to a time period in (A) positions along a SWNT, each peak corresponds to a time period in (A).

J. Zhang et. al., Nature Materials, 2007, 6, 283

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Cap-engineering for Growing SWNT with Controlled Chiralities

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Growth Mechanism of SWNT

1. Cap formation on catalysty

2. Carbon atoms bound to the cap

Tip growth

bound to the cap and form a

SWNT

www.adm.hb.se/~KIB/nanotubes.htm

Base growth

The cap structure determines the structure of the formed SWNT.

However, it is hard to control the cap structure by controlling the

t t f t l t ti l

structure of catalyst nanoparticles.

It follows the Vapor – Liquid – Solid (VLS) Mechanismp q ( )

(40)

Our Strategies --- Cap-engineering

Based on the concept of SWNTs Cloning, using a open end SWNT or opened Cp ₆₀₆₀as seed/cap to grow SWNT. The structure of the open end p g p

SWNT or opened C₆₀determines the structure of the formed SWNT.

Open-end SWNT as seed/cap Opened C₆₀ as seed/cap

Vapor-Solid Growth Mechanism / Open-End Growth Mechanismp p

(41)

Our experimental scheme

A B C

Original “seed” catalyst EBL+O₂plasma Second growth

(42)

Cloning SWNTs on Quartz Surface Tube length

15 2m 16 2m g 15 8m 16 6m

increase:

0 m – 1m

15.2m

5 m

16.2m

5 m

15.8m 16.6m

0 m 1m

15 0 10 0 6.8 15.6m 6.8

5m

5m 5 m5 m

15.0m 10.0m 10.3m

5 m 5 m

6.6m Rate of success 7.5m

for cloning:

5 m 5 m

 g

24/59 = 40.7%

Before growth After growth



(43)

6.3m

192.8 cm^-1

(i) quartz

6.3m

7.8m

nsity

﹡ ﹡

quartz

8.0m

Inten

5 m

100 200

6.3m

7.5m

8.7m Raman Shift (cm^-1) 5

h d Tube diameter & chirality

unchanged

shortened

increased

y keep unchanged after

cloning growthg g

(44)

Cloning SWNTs on SiO₂/Si Surface

Tube length

increase: increased

increase:

0 m – 4.6 m

increased

Rate of success increased

Rate of success for cloning:

56/600 = 9 3%

increased

56/600 = 9.3%

• CH₄/C₂H₄/H₂=100/5/300

• Growth T=975^oC for 15min

f

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2 ²

2 site 1

1 2

3 4

ght (nm) 0 1

0

0 1

0

1 m 1 m Heig

0 2

0 1

4

0 1

0

2 3

Distance (m)

0 1

303 SiO /Si

﹡

5

sity 6

SiO₂/Si

252.7 cm^-1

2m

66

2m

Intens 252.7 cm

2 m

55

2 m

250 300

Raman Shift (cm^-1)

AFM and Raman evidence for the diameter & chirality maintenance AFM and Raman evidence for the diameter & chirality maintenance

J. Zhang et al., Nano Lett., 2009, 9, 1673

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Open-End Growth Mechanism

“VS” growth model ?

(47)

Using C₆₀ cap to grow SWNTs

(48)

Experiments

Thermal oxidation to open the cage

Fullerendione Cap with amorphous carbon Fullerendione Cap with amorphous carbon

Cap with hydroxy groups

Active cap

SWNT

(49)

Growing SWNTs Using Opened C₆₀ as Seeds:

Growth Result

(50)

Evidence of SWNTs Grown from Opened C₆₀

Morphological a SWNTgrown from opened C₆₀and after heat treatment

SEM image of a SWNT grown from opened C₆₀and XPS of the SWNTs sample

Water treatment at 900^oC

Without water

treatment at 900^oC

Water treatment is very important for SWNTs growth!

(51)

Different thermal oxidation temperature

400 ºC c

a b

100μm

f

100μm

100μm 10μm

d e

100μm

10μm 100μm

(a)-(e) SWNTs grown from fullerendione using thermal oxidation temperatures of 300, 350, 400, 450 and 500 ^oC respectively. (f) SWNTs grown from pristine C using an oxidation temperature of 500 ^oC

grown from pristine C₆₀ using an oxidation temperature of 500 ^oC

(52)

Diameter Distribution of SWNTs grown by using Opened C caps

Opened C₆₀ caps

Diameter distribution of SWNTs grown from fullerendione under different oxidation conditions (measured from AFM)

different oxidation conditions (measured from AFM).

J. Zhang et al., Nano Lett., 2010, 10, 3343

(53)

Possible Growth Mechanism

Thermal

oxidation Open-end

growth growth

Thermal oxidation

Annealing Open-end

growth

The caps from C₆₀ has a discreet diameter distribution.

The formed SWNTs are expected to have a discreet diameter distribution.

(54)

(55)

Summaryy

Single-Walled Carbon Nanotubes

Application the SWNTs in Future Devicespp

Growing SWNTs on Surface Growing SWNTs on Surface

with Controlled Structures

Although it is still difficult to make a precise control of the diameter, chirality and local band structure of single-y g walled carbon nanotubes, there exists a big space for further efforts.

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Acknowledgement g

Fund Support:

Collaborates:

pp

NSFC (20725307, 50521201);

MOST(2006CB932701)

Prof. Zhongfan Liu PKU

Prof. Jing Kong MIT

MOST(2006CB932701) Prof. Mildred Dresselhaus MIT

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