Kinetics of transient electroluminescence in organic light emitting diodes

Abstract

Mathematical simulation on the rise and decay kinetics of transient electroluminescence (EL) in organic light emitting diodes (OLEDs) is presented. The transient EL is studied with respect to a step voltage pulse. While rising, for lower values of time, the EL intensity shows a quadratic dependence on (t − tdel), where tdel is the time delay observed in the onset of EL, and finally attains saturation at a sufficiently large time. When the applied voltage is switched off, the initial EL decay shows an exponential dependence on (t − tdec), where tdec is the time when the voltage is switched off. The simulated results are compared with the transient EL performance of a bilayer OLED based on small molecular bis(2-methyl 8-hydroxyquinoline)(triphenyl siloxy) aluminium (SAlq). Transient EL studies have been carried out at different voltage pulse amplitudes. The simulated results show good agreement with experimental data. Using these simulated results the lifetime of the excitons in SAlq has also been calculated.

Design and optimization of a blue fluorescent microcavity-organic light-emitting diode (MOLED) on AZO anode for an algae excitation light source application

“…External quantum efficiency calculations were made as reported by Shukla et. Al [19] by the J-L-V and EL spectra. The angular dependence of the EL intensity and corresponding spectra were also measured with a home-made set-up including a motorized goniometer.…”

The temperature difference compensation effect of BCP-based OLEDs by variable temperature transient electroluminescence

“…The transient electroluminescence (EL) measurement technology is widely used to investigate the carriers transport, accumulation and capture in organic thin films [6,7]. People have done a series of studies on the carriers transport process in OLEDs by using transient EL measurement technology, including the transient characteristics and the capacitance characteristics of OLEDs [8][9][10][11][12][13][14][15]. Our research group has studied the influence of the hole injection barrier, driving voltage and electron transport layer on carrier transport, and achieved some results.…”

Transient Current Response Characteristics in MoO3-Based Organic Light-Emitting Diodes

“…For the advantages of low driving voltage, fast response, wide view angle, and flexible characteristics, organic light-emitting diodes (OLEDs) have attracted widespread interest and research. − Response characteristics are important in fast display devices and infrared upconvertors. , In our previous investigation we reported that the transient electroluminescence (EL) was influenced by hole injection barrier, device structure, and light-emitting materials; e.g., the delay and decay time of transient EL were influenced by the insertion of MoO 3 . As a buffer layer, MoO 3 improved brightness and efficiency significantly by lowering the hole injection barrier.…”