Low Work Function MgAg-Coated Poly(ethylene terephthalate) Films for Organic Light-Emitting Device Fabrication with Lamination Process

We have demonstrated the laminated organic light-emitting devices (OLEDs) with a MgAg precoated poly(ethylene terephthalate) (PET) film. The MgAg-coated PET film maintained a low work function after several days of storage. Although the performance of the laminated OLEDs strongly depended on the adhesion of the cathode film, the best performance of the laminated OLED with the PET cathode film based on poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) showed comparable performance to the cathode vacuum deposited reference device. The electronic junction formed by lamination might still be inferior to that formed by the thermal evaporation of metals at present from the viewpoint of operation voltage. However, the comparable current efficiency and maximum luminance of the laminated OLED implied that the prepared PET with the MgAg cathode probably maintained a high activity. We believe that better laminated OLEDs might be obtained if better light-emitting polymers are employed.