저널

To study the characteristics of AC driven OLED, we fabricated the fluorescent OLEDs and analyzed the electroluminescence characteristics of OLEDs with AC negative voltage. The luminance and the current density of the OLED decreased, and the number and size of the dark spots increased in proportion to the duration time and level of the applied AC negative voltage. The current efficiency of the OLED was improved when high AC negative voltage was applied within a short time. When the AC negative voltage of 10 V was applied for 1 minute, the efficiency was improved by 12.4%. Also, the degradation of luminance and current efficiency due to the duration of light emission was improved in the case of OLED applied for 1 minute with 10 V AC negative voltage. These are expected as a result of the improvement of the leakage current characteristics by eliminating the short-circuit region formed by the defect of the OLED at the AC negative high voltage. As a result, the continuous application of AC negative voltage reduced the luminance and the current density of OLED, but the temporary application of AC negative voltage with the proper time and voltage could improve the efficiency and lifetime of OLED.

OLED;Alternating current;Negative voltage;Reverse aging;Dark spot;