Current-Voltage-Luminance Characteristics Depending on a Direction of Applied Voltage in Organic Light-Emitting Diodes

Abstract

We have investigated current-voltage-luminance characteristics of organic light-emitting diodes based on TPD/Alq3 organics depending on the application of forward-backward bias voltage. Luminance-voltage characteristics and luminous efficiency were measured at the same time when the current-voltage characteristics were measured. We have observed that the current-voltage characteristics shows a reversible current maxima at low voltage, which is possibly not related to the emission from Alq3. Current-voltage-luminance characteristics imply that the conduction luminance mechanism at low voltage is different from that of high voltage one.