Supplementary Material (ESI) for Journal of Materials Chemistry

This journal is (c) The Royal Society of Chemistry 2009

Electronic Supplementary Information for

Colloidal approach for tungsten oxide nanorod-based electrochromic systems with highly improved response times and color efficiencies

So Yeon Park,a Ji Min Lee,b Changho Noh,b and Seung Uk Son*a Department of Chemistry, Sungkyunkwan University, Suwon 440-746, Korea

and Samsung Advanced Institute of Technology(SAIT), Suwon 440-600, Korea

Figure S1. Low magnification TEM image of tungsten oxide nanorods used in this study.

Supplementary Material (ESI) for Journal of Materials Chemistry

This journal is (c) The Royal Society of Chemistry 2009

Figure S2. Magnified SEM image of W300-(12 w%) (after Pt coating).

Supplementary Material (ESI) for Journal of Materials Chemistry

This journal is (c) The Royal Society of Chemistry 2009

Figure S3. TEM image of a piece of film [W300-(12 w%)] and thickness distribution diagram of rods in film.

2.4 2.6 2.8 3.0 3.2 3.4 3.60

5

10

15

20

25

Freq

uenc

y (%

)

Thickness (nm) of Rods in W300

(a)

(b)

Supplementary Material (ESI) for Journal of Materials Chemistry

This journal is (c) The Royal Society of Chemistry 2009

Figure S4. IR-spectra of oleylamine and W300 (before and after heating).

4000 3500 3000 2500 2000 1500 1000

Tran

smitt

ance

(%)

Wavenumber (cm-1)

Oleylamine

W300-Before heating

W300-After heating

Supplementary Material (ESI) for Journal of Materials Chemistry

This journal is (c) The Royal Society of Chemistry 2009

Figure S5. UV/vis absorption spectrum of W300 at colored state and bleached state.

500 600 700 800 900

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

Bleached State

Colored State

A

bsor

banc

e (O

.D.)

Wavelength (nm)

Supplementary Material (ESI) for Journal of Materials Chemistry

This journal is (c) The Royal Society of Chemistry 2009

Figure S6. The color efficiencies of the tungsten oxide film prepared at 300oC..

0 2 4 6 8 100.0

0.2

0.4

0.6

0.8

107cm2/C

112 cm2/C

132 cm2/C

141 cm2/C

W300-3 w%

W300-6 w%

W300-8 w%

W300-12 w%

ΔOD

Charge Density (mC/cm2)