Mr. LE, Cong Duy (3rd -year doctoral student in Murata lab of Applied Physics Area) received Best Poster Presentation Awards in the 12th Asian Conference on Organic Electronics (A-COE 2020).

Asian Conference on Organic Electronics (A-COE) provides a premier platform to the research personnel predominantly from Asia and Asia-pacific for the exchange of stimulating ideas, in-depth discussions, and share the latest research data in the field of cutting-edge research topics related to OLEDs, OPVs, DSCs, perovskite based electronics, OFETs, OLETs, organic memories, sensors, emerging organic electronics and so on.
A-COE 2020 was held as an online and offline hybrid conference, during November 8-10, 2020.

■Date Awarded
November 10, 2020

■Title
Extended Lifetime of Fluorescent Organic Light Emitting Diodes by Combining Ultra-Clean Fabrication Conditions and Annealing after Device Fabrication

■Authors
Duy Cong Le and Hideyuki Murata

■Abstract
We have previously demonstrated that stability of organic light emitting diodes (OLEDs) is governed by the amount of residual water in an evaporation chamber. To further remove the residual water, two non-evaporable getter pumps (NEGP) were added to the evaporation chamber pumped with tandem turbo molecular pumps (TMP). The lifetime at which luminance reaches to 90% of the initial luminance (LT₉₀=136 h) of devices fabricated with NEGP (OLED-NEGP) showed significant improvement (more than 5 times) than that (25 h) without NEGP (OLED-TMP). We further improve the device LT₉₀ by annealing the device after fabrication. The LT₉₀ (236 h) of the annealed OLED-NEGP showed 9.4 times longer lifetime than that of OLED-TMP. From detailed analysis of photoluminescence lifetime and morphological measurement, the improvement in the stability of annealed OLED-NEG is ascribed to the increase in the density of the hole transport layer.

■Comment
I am honored to receive the award for the best poster presentation of 12th A-COE conference. I acknowledge my supervisor, Prof. Hideyuki Murata for his guidance. I acknowledge members in Murata laboratory for their assistance. I also acknowledge my wife, Linh for consistently inspiring me during my graduate study. Finally, I am indebted to my parents for their reliable supports.

December 4,2020