EFFECT OF DISCHARGE TIME ON THE LUMINANCE OUTPUT OF ORGANIC LIGHT EMITTING DIODE (OLED)

Abstract

Due to its thin geometry, the luminance output of an OLED can be profoundly affected by the presence of unwanted charge due to capacitance effect. Thus, the optimum discharge time is necessarily crucial to be identified, so that the occurrence of the surplus charge can be fully terminated. However, studies on the discharge time of OLED were occasionally reported, indicated that this issue remains unexplored. Therefore, the objective of this paper was to study the effect of discharge time on luminance output of OLED. In this study, the on/off cycles approach was employed by which the OLED samples were switched-on (T_on) and -off (T_off) at specific times. With constant voltage and current supply, the T_on was fixed at 1 s, whereas the T_off were validated at 1 s, 10 s, 20 s, 30 s and 40 s. The stability of luminance output was captured by using a chroma-meter, carried out in an in-house black-box. The optimum discharged time was found at T_off 40 s and the results demonstrated that the luminance output was mostly dependent on the discharge time. The attained data emphasized the significance of determining the optimum discharge time of OLED to ensure the luminance output is accurate and reliable.