Appendix A. Supplementary data

SEM images of PDMS layers before and after VUV irradiation (Fig. S1), Decrease of shear

viscosity and film thickness of PDMS precursor diluted with cyclosiloxane D5 (Fig. S2), AFM

surface images of PDMS without and with dilution of precursor (Fig. S3), XPS elemental

analysis depth profile for the PDMS/SiOx multilayer prepared with different VUV radiation time

(Fig. S4), Structure of the standardized OLED device for stability test (Fig. S5), Current-

Voltage-Luminance characteristics for the OLEDs with and without TFE encapsulation (Fig.

S6).

Before VUV After VUV

PDMSDiluted with D5

PDMS

Fig. S1. Scanning electron microscope (SEM) images of PDMS layers before and after VUV irradiation for 1 min for the thick film (~7.5 µm) prepared from un-diluted coating solution and the thin film (460 nm) prepared from 5 times diluted solution with D5.

100 80 60 40 20 0

0

2000

4000

6000

8000

Film thickness Viscosity

Concentration of PDMS precursor (wt%)

Film

Thi

ckne

ss (n

m)

1

10

100

1000

10000Viscosity (m

Pa.s)

Fig. S2. Decrease of shear viscosity and film thickness by dilution of PDMS precursor (1:1 mixture of oligomer and cross linker by weight) with cyclosiloxane D5. Conditions of spin-coating were 6,000 rpm and 30 s. The viscosity of diluted PDMS solution was determined at low shear rate of 1 s-1.

Image Surface Area 512659 nm²Image Projected Surface Area 250000 nm²Image Surface Area Difference 105 %Image Rq 6.55 nmImage Ra 5.27 nmImage Rmax 49.8 nm

Image Surface Area 537434 nm²Image Projected Surface Area 250000 nm²Image Surface Area Difference 115 %Image Rq 7.03 nmImage Ra 5.65 nmImage Rmax 52.4 nm

(b) PDMS diluted with D5(a) PDMS

Ra=5.27 nm Ra=5.65 nm

Fig. S3. AFM surface images of a) PDMS without dilution of precursor (~7.5 µm thick) and b) PDMS with 5 times dilution of precursor (460 nm). The same UV curing for 1 min has been applied. Reticulated surface morphology of PDMS as well as average surface roughness, Ra, are unchanged by dilution of precursor.

0 100 200 300 400 500 600 7000

20

40

60

80

100

Ato

m %

Depth (nm)

Si O C

(a)

0 100 200 300 400 500 600 7000

20

40

60

80

100

Ato

m%

Depth (nm)

Si O C

(b)

0 100 200 300 400 500 600 7000

20

40

60

80

100

Ato

m%

Depth (nm)

C O Si

(c)

Fig. S4. XPS elemental analysis depth profile (C, O and Si) measured upon Ar+ beam etching for the PDMS/SiOx/PDMS/SiOx/PDMS/SiOx/PDMS 3.5 dyads on Si single crystal substrates, prepared with VUV radiation for a) 1, b) 3 and c) 20 min / coating.

Glass substrate

Anode (ITO 150 nm)HIL (HAT-CN 15 nm)

HTL (NPD 25 nm)

EML(CBP：Ir(ppy)3 (6wt%)

(35 nm)

ETL (Alq3 40 nm)HBL (BAlq 10 nm)

EIL (LiF 0.7 nm)Cathode (AL 100 nm)

TFE

Glass substrate30 ×  30 mm2

Patterned ITO 13.9 ×  2.2 mm2

Al electrode 20 ×  2 mm2

TFE encapsulationarea

Stacks of organic layers 12 ×  12 mm2

4 mm 4 mm

Fig. S5. Structure of the standardized OLED device for stability test. (left) horizontal sketch of the OLED stack, (right) picture of the entire device with 4 emissive areas indicated by green (2 × 2 mm2 ). Tin doped Indium oxide (ITO) coated glass substrates (Atsugi Micro) were used as anodes. All the organic layers as well as Al cathode on top were prepared by sequential vacuum evaporation. HIL (hole injection layer), HTL (hole transport layer), EMI (emissive layer), HBL (hole blocking layer), ETL (electron transport layer), EIL (electron injection layer) were dipyrazino[2,3-f:2′,3′-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN, Taiwan e-Ray), N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPD, Taiwan e-Ray), 4,4′-N,N′-dicarbazole-biphenyl (CBP, Taiwan e-Ray) doped with 6 wt% of tris(2-phenylpyridine)iridium(III) (Ir(ppy)3, Chemipro Kasei), Bis(8-hydroxy-2-methylquinoline)-(4-phenylphenoxy)aluminum (BAlq, Taiwan e-Ray), tris(8-hydroxy-quinolinato)aluminum (Alq3, Taiwan e-Ray), lithium fluoride (LiF, Kojundo Chemical), respectively. The emissive was regulated by the overlap of ITO pattern and Al cathode. The complete devices were transferred to nitrogen-filled glovebox (O2, H2O <10 ppm) for the encapsulation. Two sides of the substrate were masked with strips of polyimide tape (4 × 30 mm2) before coatings with TFE to leave conductive surface.

4 5 6 7 8 9 10 11

0

10

20

30

40

50 Bare OLED TFE encapsulation

Voltage (V)

Cur

rent

den

sity

(mA

/cm

2 )

1x101

1x102

1x103

1x104Lum

inance (cd/m2)

Fig. S6. Current-Voltage-Luminance characteristics for the OLEDs with and without TFE encapsulation, showing no damage by the solution processing of TFE developed in this study.