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 and an interlayer dielectric material between a gate electrode of a thin-film transistor of a driving circuit and a channel of the thin-film transistor. The improved structure of the driving circuit facilitates a higher voltage range for controlling the gray level of the pixels, and may increase the aperture ratio of the pixels.