Organic optocoupler consisting of an optimized blue organic light emitting diode and an organic photoconductor

Abstract

We present an optocoupler device based on a blue organic light-emitting diode (OLED) as input unit, and a pentacene photoconductor as output unit. The optocoupler was realized on a transparent glass substrate. The luminance was found larger than 103cd/m2 with a blue peak emission at 450nm for the optimized ZnO (120nm)/ITO (150nm)/α-NPB (40nm)/BCP (15nm)/Alq3 (20nm)/Al structure. The Ids-Illum/Ids-Dark current ratio, the sensitivity and the current density transfer ratio of the optocoupler are of about 7, 10−1A/W, and 10−1, respectively. The rise as well as full times were found faster for high bias voltages. The equilibrium regime with less persistent current was reached more quickly, as evidenced by the fast current response for higher bias voltage, indicating a more favorable recombination processes of the charge carriers. The organic optocoupler with a blue OLED reveals promising results; thus, it can be investigated as a good candidates for practical uses in organic optoelectronic circuits with high bias voltages.