Fig. 4: Bending characteristics of textile-based OLEDs.

a Photographs (top and side view) of the textile-based OLEDs during repetitive bending with a 1.25 mm curvature radius. Current density (J)-luminance (L) graph according to a repetitive bending test of the textile-based OLEDs before and after bending under a bending radius of (b) 1.5 mm and (c) 1.25 mm, 1000 cycles, respectively. d Ratio of the luminance to the current density (the slope in the current density- luminance graph) at bending radii ranging from 3 mm to 1.25 mm.