31-Inch AMOLED Display Integrating Gate Driver by Metal-Oxide TFTs

A gate driver on array (GOA) circuits employed with amorphous indium-gallium-zinc oxide (IGZO) based thin film transistors (TFTs) have been successfully utilized to generate the driving signals for the commercialization of active matrix organic light-emitting diode (AMOLED) displays. The depletion-mode TFTs in GOA circuits can be completely turned off by the introduction of series-connected two-transistor and dual low voltage level power signals. Simulation results demonstrate that GOA exhibits high process stability with threshold voltage margin from -5V to +5V. Furthermore, GOA output characterization and mobility compensation effect are evaluated by the integration of GOA and pixel in a 31-inch 4K AMOLED display. Experimental results demonstrate that full swing driving pulses can be obtained by GOA. Finally, the stripe mura in display caused by mobility variation can be successfully eliminated by the introduction of GOA circuits.