Emission and degradation mechanism of polymer light emitting diode (PLED) was investigated by using trap analysis.
The device structure in this study is ITO/PEDOT-PSS/LEP/Ba/Al, where LEP (light emitting polymer) is polyfluorene
type Lumation Green 1300 series supplied from Sumation Co., Ltd. The trap behaviors of virgin and degraded devices
were investigated by using the bipolar devices, the hole only devices and the electron only devices. By analyzing the
results, we successfully clarified depth and density of each trap at the interfaces and bulks of this PLED device. PL aging
behavior and EL aging behavior were also examined for investigating mechanisms. This study shows such novel
information that carrier traps at the PEDOT-PSS/LEP interface play an important role in emission and degradation characteristics.