P‐32: Investigation on Mechanism of Illumination Mura in AMOLED Display with LTPS‐TFT Backplane after Long Term Localized Illumination

Low‐temperature polycrystalline silicon (LTPS) thin film transistors have been widely used in AMOLED display applications due to the high mobility and the capability of realizing peripheral and active matrix circuits on glass. Though LTPS TFTs exhibited relatively good electrical performance and stability, illumination Mura on AMOLED display with LTPS backplane could be observed by naked eye after several hours’ illumination on localized display area. The Mura boundary separates the areas with and without illumination when the AMOLED display is lighted on without pattern. The electrical instability of LTPS TFT was proved to be the main underlying cause. The DTFT threshold voltage compensation effect and SS variation in 7T1C pixel circuit has certain relationship with the illumination Mura detail.