The International Meeting on Information Display (IMID), jointly organized by the Society for Information Display (SID) and the Korean Information Display Society (KIDS), has been held annually since 2001. It is one of the world's top three international conferences for sharing the latest knowledge in the field of information display. At IMID 2024, over 2,300 participants from 18 countries attended, with more than 950 presentations given. Master's student Han-sol Choi received the 'Best Poster Paper Award' for presenting a poster on the topic 'Analysis of Electrostatic Discharge (ESD) Damage in Quantum Dot Light-Emitting Diodes: From Pixel to System Level.' This research was conducted in collaboration with Professor Hyung-jun Song's research team (Department of Safety Engineering) at Seoul National University of Science and Technology.

Quantum dot light-emitting diodes, which utilize quantum dots known for their high color purity and low processing cost, are gaining attention as next-generation display devices. Inkjet printing is emerging as an effective processing method for quantum dot light-emitting diodes. However, there is a lack of analysis on damage caused by high voltages that may occur during the manufacturing process, which is crucial for the stable production of display products.

The inkjet printing process involves high voltages from roll-to-roll, inkjet heads, and thin-film detachment, which can lead to damage in quantum dot light-emitting diodes. By applying high voltage to the quantum dot light-emitting diode device through electrostatic discharge, the electrical characteristics were analyzed, observing an increase in leakage current and impedance as well as a decrease in luminance. Optical analysis further revealed damage to the light-emitting surface under high voltage conditions.

The damage mechanism of quantum dot light-emitting diodes caused by electrostatic discharge was identified, with observations including phenomena such as mixing or detachment of the anode within the device. Furthermore, it was discovered that when high voltage is applied to one device within a quantum dot LED panel arranged in a matrix, the same damage mechanism occurs in other devices sharing common electrodes with the affected device.

This research was supported by the University-Focused Research Institute and Basic Research programs (2018R1A6A1A03025242, 2022R1F1A1066526).

 (From left) Current density-voltage characteristic curve of quantum dot light-emitting diodes with increasing electrostatic discharge voltage, reduction of the light-emitting area with increasing voltage, and energy-dispersive spectroscopy (EDS) analysis results of damaged quantum dot light-emitting diodes＞