Devices and methods for increasing the aperture ratio and providing more precise gray level control to pixels in an active matrix organic light emitting diode (AMOLED) display are provided. By way of example, one embodiment includes disposing a gate insulator between a gate of a driving thin-film transistor and a gate of a circuit thin-film transistor. The improved structure of the display facilitates a higher voltage range for controlling the gray level of the pixels, and may increase the aperture ratio of the pixels.