Analysis and control of the active area scaling effect on white organic light emitting diodes towards lighting applications

The authors investigate the scaling of the performances on white organic light emitting diode in devices having active regions ranging from 0.25 to 9 cm². They observe a drop in the luminance and in the current density with increasing active area of the devices. A model where both these effects are ascribed to the spread of the current leakage on the indium tin oxide surface is proposed. To limit the consequences of these effects on the device performances, they insert a pattern of metal stripes onto the anode contact. This results in a device with a maximum luminance of 1800 cd/m² on a surface of 9 cm².