Electrostatic Damage Influenced by Bottom Gate-Like Effects in Flexible Organic Light-Emitting Diodes

Electrostatic damage has been shown to be a common phenomenon in display applications especially in flexible organic light-emitting diodes (OLEDs). Herein, to analyze the damage formation process and the internal physical mechanism, a bottom gate-like effects model based on the accumulation of negative charges under a thin film transistor (TFT) channel was proposed. The results after electro-static discharge (ESD) test substantiated that the threshold voltage (
$\text{V}_{\text {th}}{)}$
was positively shifted and the subthreshold swing (SS) was increased, which caused the luminance variation of flexible OLEDs. Furthermore, these changes can also be reproduced by applying a voltage under the samples, which is an analogy to the bottom gate-like effects. In order to alleviate the electrostatic damage influences, hydrogen plasma was adopted as an interface modification method to enhance the stability of TFT under electro-static discharge conditions. The research opens the possibility of considering more relationship between the display performance and the microscopic charge behaviors for their actual applications.