Stretchable Organic Light‐Emitting Devices with Invisible Orderly Wrinkles by using a Transfer‐Free Technique

Abstract

Abstract Stretchable organic light‐emitting devices (SOLEDs) based on orderly wrinkles have become a promising candidate for the new‐generation deformable displays because of their high‐optoelectronic performance and stretching stability. However, the complex thin film transfer process to form the wrinkles and the decreased display quality caused by the large‐period wrinkles with a few hundreds of microns are obstacles to their practical applications. Herein, a simple transfer‐free technique is designed to introduce the orderly wrinkles with a much smaller period of 70 µm into the SOLEDs, which is the smallest value reported to date for the orderly wrinkles integrated in the SOLEDs. The small‐period wrinkles are invisible by naked eyes and beneficial to the applications of the SOLEDs in high‐quality stretchable displays. The electroluminescence performance of the SOLED with 20% stretchability are comparable to those of the rigid OLEDs on glass substrates. After 2000 cycles of stretching, the luminance of the device remained at 90% of its initial value. Meantime, the transfer‐free technique is compatible with the flexible encapsulation process. The luminance of the encapsulated SOLEDs exhibit negligible decline after 600‐min continuous operation under ambient condition. This work provides an effective solution for achieving high‐performance SOLEDs by a simple process.