Improvement in image quality of a 5.8-in. OTFT-driven flexible AMOLED display

The image quality of an OTFT-driven flexible AMOLED display has been improved by enhancing the performance of OTFTs and OLEDs. To reduce the operating voltage of OTFTs on a plastic film, Ta2O5 with a high dielectric constant was used as a gate insulator. The organic semiconductor layer of the OTFT was successfully patterned by a polymer separator, which is an isolating wall structure using an organic material. The OTFT performance, such as its current on/off ratio, carrier mobility, and spatial uniformity on the backplane, was enhanced. A highly efficient phosphorescent OLED was used as a light-emission device. A very thin molybdenum oxide film was introduced as a carrier-injection layer on a pixel electrode to reduce the operating voltage of the OLED. After an OTFT-driven flexible AMOLED display was fabricated, the luminance and uniformity on the display was improved. The fabricated display also showed clear moving images, even when it was bent at a low operating voltage.