fig16

Figure 16. Display applications utilizing buckling-structured flexible films. (A) Schematic diagram of the concept for an OLED with an invisible wrinkle structure, surface SEM and light luminescence images before and after stretching, based on the dimensions of the wrinkle structure introduced on the TFLED device substrate. Reproduced with permission^[140]. Copyright 2020, Wiley-VCH; (B) Photographs of a pre-strained, wavy QD-LED. The inset shows a magnified SEM image (scale bar, 300 μm), buckling structure of the flexible substrate under tension and the R/G/B luminescence characteristics of stretchable QD-LEDs under stretching and bending conditions. Reproduced with permission^[141]. Copyright 2017, American Chemical Society; (C) SEM images and photographs of SOLEDs captured in a dark environment under tensile strains of 0%, 50%, and 100%. Reproduced with permission^[142]. Copyright 2018, Nature Publishing Group. OLED: Organic light-emitting diode; SEM: scanning electron microscope; TFLED: thin-film light-emitting diode; QD-LED: quantum dot light-emitting diode; SOLEDs: stretchable organic light-emitting devices.