P‐1.3: Comparision of two different a‐IGZO TFT Gate Driving Circuits for 32‐in FHD TFT‐LCD

Two different a‐IGZO gate driving circuits (GOA) which used long channel length (GOA_A) and STT (GOA_B) structures were designed and compared. GOA_B shows better performance than that of GOA_A, while the Vth of T53 in GOA_B circuit would shift to a very positive voltage after life test. The large channel width size ratio between T53 and T54 would bring about bigger Vds voltage of T53 which induces large current stress of T53 in GOA_B, so the Vth voltage of T53 in GOA_B would shift to a very positive voltage at life test. The phenomenon which T53 devices were easy to shift to positive bias can be restrained and improved by new design of its pull down holding part in GOA_B by spice simulated results.