The invention is directed to an improved organic electroluminescent device. In one embodiment, the OLED includes a thin film transistor formed in a non-emission region on an insulating substrate that also includes source and drain electrodes. The OLED further includes a lower electrode formed in an emission region on the insulating substrate and connected to one electrode of the source/drain electrodes through a contact hole. The OLED yet further includes an organic emission layer formed in the emission region on the lower electrode, and an upper electrode formed on the organic emission layer, wherein the lower electrode has a surface with its corners rounded off. The lower electrode acts as a pixel electrode. Having its surface with corners rounded off prevents short-induced defects caused by outgassing.