Fig. 4: Cross-sectional morphology and WVTR testing before and after bending.

a, b SEM image of the cross section of wrinkle Al2O3 film. c Optical microscope images of 500 cycles wrinkle Al2O3 before and after bending at RT. d WVTR of 500 cycles wrinkle Al2O3 at RT before and after bending from 1/R-Time curve. e Optical microscope images of 500 cycles PEALD-Al2O3 before and after bending at RT. f WVTR of 500 cycles PEALD-Al2O3 at RT before and after bending from 1/R-Time curve. g Optical microscope images in all directions of bending and before and after bending. h WVTR changes after all directions bending from 1/R-Time curve.