Abstract: In the fabrication of a display, such as an OLED display, the OLED layer stack is deposited on an electrode on the substrate. The electrode may be the anode and may comprise indium tin oxide (ITO). Desirably, the deposited films are of uniform thickness over the entire active area of the electrode. If the films are not uniform, then areas that are thicker will not emit light, and areas that are too thin may emit light in a less than optimum efficient way (power loss) and/or result in leakage current leaks through the device in a way that does not generate photons. An active-matrix organic light emitting diode comprises a substrate with a larger well size or wider channel width compared to the emission area. This improves the effective aperture ratio, which improves pixel intensity homogeneity.