Supplementary Material

Low Power Stretchable Active-Matrix Red, Green, Blue (RGB) Electrochromic Device Array of Poly(3-methylthiophene)/Prussian blue

Dong Sik Kim,a Heun Park,a Soo Yeong Hong,a Junyeong Yun,a Geumbee Lee,b Jin Ho Lee,b

Lianfang Sun,c Goangseup Zi,c and Jeong Sook Haa,b*

a. Department of Chemical and Biological Engineering, Korea University, 145 Anam-ro,

Seongbuk-gu, Seoul 02841, Republic of Korea

b. KU-KIST Graduate School of Converging Science and Technology, 145 Anam-ro,

Seongbuk-gu, Seoul 02841, Republic of Korea

c. Department of Civil, Environmental and Architectural Engineering, Korea University, 145

Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea

*Corresponding author. Tel.: +82-2-3290-3303. E-mail: jeongsha@korea.ac.kr (Jeong Sook

Ha)

1

Figure S1. Optical images of the grown a) P3MT and b) PB films with variation of the

growth conditions.

2

Figure S2. (a) Scheme of P3MT ECD. (b-d) UV-Vis spectra of P3MT ECD for various

electrodeposition cycle conditions of (b) 1 cycle, (c) 3 cycles, and (d) 5 cycles, respectively.

3

Figure S3. (a) Scheme of PB ECD. (b-c) UV-Vis spectra of PB ECD for different

electrodeposition times of (b) 100 s and (c) 300 s, respectively.

4

Figure S4. Cross-sectional SEM images of a) P3MT and b) PB.

5

Figure S5. AFM images and line scans for a) P3MT and b) PB

6

Figure S6. AFM images for (a) P3MT grown for 1 cycle and (b) PB grown for 100 s,

respectively.

7

Figure S7. Nyquist plot of the device consisted of ITO//electrolyte//ITO. The inset is an

enlargement of the high frequency region

8

Figure S8. Color of the ECD for different applied voltages, expressed in the CIE 1931 color

space. The colors of the ECD at -1.0 V, 0 V, and 1.0 V correspond to the coordinates of (0.41,

0.32), (0.31, 0.34), and (0.27, 0.30), respectively.

9

Figure S9. Transmittance change over a period of 300 s, for an applied voltage of 1.0 V.

10

Figure S10. Current density for driving the P3MT/PB ECD with an applied bias voltage of a)

-1.0 V and b) 1.0 V.

11

Figure S11. Open-circuit memory of P3MT/PB ECD for (a) short time and (b) long time,

respectively.

12

Figure S12. The color change of P3MT/PB ECD containing bubbles with time under applied

voltage of -1.0 V.

13

Figure S13. Response time of P3MT/PB ECD under bending at a bending radius of 2.5 mm.

14

Figure S14. Definition of biaxial strain in unit cell.

15

Figure S15. a) Scheme of an ECD attached to Ecoflex substrate and its structure. b) Optical

microscopic image of an ECD attached to Ecoflex substrate, sequentially taken during biaxial

stretching/releasing process.

16

Figure S16. Normalized transmittance of one pixel of a 4 × 4 AM ECD array against number

of stretching iterations.

17

Figure S17. Optical microscope images of the stretchable 6 × 6 AM ECD array before and

under 30 % biaxial stretching, respectively. Here, only the ECDs in the 4th line are selectively

colored in red.

Table S1. Performance of wearable ECDs.

18

Electrochromic

Materials

Operation

Voltage [V]Color Display

Cycle

Durability

Coloration

Efficiency

[cm2 C-1]

Power

Consumption

[μW cm-2]

Deformability Ref.

WO3∙2H2O -3.0 ~ 3.0 Black↔Transparent N.A. 38.5 N.A. Flexible [1]

MV(PF6)2 -0.9 ~ 0 Blue↔Transparent N.A. 105900

(at -0.9 V)Flexible [2]

PANI//V2O5 -2.5 ~ 2.5Yellow↔Green↔

Blue

After 180th

cycle, 19 %

decay of ΔT

65.441140

(at 2.5 V)Flexible [3]

Heptyl Viologen -0.65 ~ 0 Blue↔Transparent

After 100th

cycle, 15 %

decay of ΔT.

31.82 N.A. Stretchable [4]

Ethyl Viologen

hydrogel-2.3 ~ 0 Purple↔Transparent

After 100th

cycle, 7 %

decay of ΔT

N.A. N.A. Stretchable [5]

P3HT -1.0 ~ 1.0 Dark red↔Pale Blue

After 90th

cycle, 14 %

decay of ΔT

N.A. N.A. Stretchable [6]

PEDOT:PSS -2.0 ~ 2.0 Blue↔Transparent

After 1000th

cycle, 28 %

decay of ΔT

100 N.A. Flexible [7]

P3MT//PB -1.0 ~ 1.0 Red↔Green↔Blue

After 180th

cycle, No

decay of ΔT

201.6331

(at -1.0 V)Flexible

This

work

Table S2. Comparison of ECD arrays: materials, color range, layout, and mechanical

properties

19

Electrochromic

MaterialsColor Display Array

Mechanical

Stability

Operation

MethodRef.

PEDOT:PSS Blue↔Transparent 6 6 Flexible Active Matrix [8]

PEDOT:PSS Blue↔Transparent 7 128 Flexible Passive Matrix [9]

PEDOT:PSS Blue↔Transparent 5 5 Flexible Active Matrix [10]

2‐(3′‐trifluoromethylphenylamino

)‐6′‐(diethylamino)fluoran

Black↔Transparent 5 × 5 RigidPassive

Matrix[11]

Bis-(2-phosphonoethyl)-4, 4′-

bipyridinium dichlorideBlue↔Transparent 3 × 3 Rigid

Passive

Matrix[12]

P3MT//PB Red↔Green↔Blue 4 4 Stretchable Active MatrixThis

work

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