Supplementary Information

for

Spray Coated High Conductivity PEDOT:PSS Transparent Electrodes for Stretchable and Mechanically Robust Organic Solar Cells

Jeffrey G. Tait,a,b Brian J. Worfolk,a,b Samuel A. Maloney,a,b Tate C. Hauger,a,b Anastasia L. Elias,a,c Jillian M. Buriak,a,b Kenneth D. Harrisa

aNational Institute for Nanotechnology, 11421 Saskatchewan Drive, Edmonton, Alberta, T6G 2M9, CanadabDepartment of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, CanadacDepartment of Chemical & Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 2V4, Canada

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Fig. S1. Thickness of spray-cast PEDOT:PSS films as a function of solution flow rate through the ultrasonic atomizing nozzle.

Fig. S2. Plot of root mean square roughness measured by AFM for a series spray coated PEDOT:PSS electrodes with different thicknesses.

0 100 200 300 400 500 6000

20

40

60

80

100

120

Glass - Sample 1Glass - Sample 2ITOPEDOT:PSSPEDOT:PSS - EG Dip - Sample 1PEDOT:PSS - EG Dip - Sample 2

Indentation Depth (nm)

Red

uced

Mod

ulus

(GPa

)ITO

Glass

PEDOT:PSS

Fig. S3. Nanoindentation data for uncoated glass (two distinct samples), thick spray coated PEDOT:PSS layers on glass (three distinct samples, two of which were soaked in EG) and ITO layers on glass.

Fig. S4. Current density vs. voltage curves for forward mode solar cells with PEDOT:PSS electrodes of various thicknesses.

Fig. S5. Scanning electron microscopy images of OSC devices with (a,b) PEDOT:PSS bottom electrodes, (c,d) ITO bottom electrodes, and all with LiF/Al top contacts. All images were obtained after bending, where ITO-based devices clearly show cracking visible through the top contact.