Flexible Organic Light-Emitting Diodes Using a Metal Peel-Off Method

Organic light-emitting diodes were fabricated on a glass-MgO_x-Ag layered substrate and separated between Ag and MgO_x interface, showing the bending properties. Adhesive force decreased from 18 to 1.4 gf/cm after insertion of the MgO_x layer between the Ag and glass. The Ag-O component in Ag 3d _5/2 spectra and O-Ag (ionic bond) component in O 1s spectra increased as the MgO_x layer was thickened. This supports that Ag oxidized to AgO_x while the thickness of MgO_x increased, resulting in a reduction of the adhesive forces of Ag layer. Therefore, it is concluded that a metal at the interface with a metal oxide is easily oxidized, reducing the adhesive forces and enabling the peel-off process.