P-type Thin Film Transistor-Like Effects in Organic Light-Emitting Diodes Array: the Origin of Lateral Leakage

The presence of lateral leakage through organic semi-conductive layers in organic light-emitting diodes (OLEDs) array prevents excellent performance of display application especially in high resolution one. To mitigate the impact of lateral leakage and figure out the detailed mechanism, an accurate model involving simultaneous measurements of OLED and organic thin film transistor (OTFT) is proposed. The results establish that the lateral leakage generates to the adjacent off-state devices due to a p-type thin film transistor-like effects with the cathode playing a gate function. The proposed technique reveals that higher gate voltage and source voltage brings in more serious lateral leakage, corresponding to the electric field effect. It also shows a temperature dependence when the environment has changed. The research opens the possibility of considering the influences of semi-conductive layers and parallel structural devices on more self-luminous arrays for their actual application.