Highly transparent and flexible fabric-based organic light emitting devices for unnoticeable wearable displays

Fabric displays integrated into clothing are important members of wearable electronics. Highly transparent and flexible organic light emitting devices (OLEDs) fabricated on fabrics can make clothing keep the original appearance and wearing comfort and so are under focused research. Indium tin oxide is the main transparent electrodes due to its high transparency. However, its brittleness makes OLEDs lack of flexibility. Here ultrathin metal films are used as anodes and cathodes in OLEDs for both high transparency and flexibility. The anode and cathode are 7 nm Au film and 9 nm Ag film respectively. As a result, the total transmittance of the OLEDs is 74% at 550 nm wavelength when combining with a capping layer. Fabric displays based on the transparent and flexible OLEDs are realized. The patterns of the fabric with different colors can be seen clearly through the OLEDs. At the same time, the fabric display can withstand a 1 mm bending radius. This is the first reported transparent and flexible fabric displays, which will be useful for smart IT devices that are comfortable and fashionable to wear.