Purification of Alq3 Using Ionic Liquids: Effects on Purity and Mobility for Improved OLED Performance

IF 2.6 4区材料科学 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Electronic Materials Letters Pub Date : 2025-05-20 DOI:10.1007/s13391-025-00577-5

Dong-Su Kim, Tae Won Ha, In Jae Park, Dae Yun Lim, Young Baek Kim, Jin Hyeok Kim, Dong Chan Shin, Chil-Hyoung Lee

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引用次数: 0

Abstract

Alq₃ exists in five crystalline phases, with the δ-phase offering excellent charge transport characteristics owing to its minimal π-orbital overlap and short intermolecular binding distance. Previously, the purification of Alq₃ to obtain this specific phase was achieved using ionic liquids instead of sublimation methods. By controlling concentration and temperature, high-purity δ-phase Alq₃ could be obtained. In this study, the effectiveness of purifying Alq₃ using ionic liquids was examined not through high-performance liquid chromatography measurements but by fabricating and characterizing organic light-emitting devices (OLEDs) to assess improvements in purity and mobility. I–V–L measurements of the fabricated devices revealed a decrease in threshold voltage, an increase in maximum luminance, and a reduction in sub-threshold swing after purification. The I–V characteristics confirmed the effectiveness of ionic-liquid-based purification in enhancing material purity. Lastly, electron-only devices were fabricated, and charge mobility was calculated using the Mott–Gurney equation. The simulation and experimental results were compared to clarify the influence of δ-phase Alq₃ purified with ionic liquids on OLED performance.

Graphical Abstract

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离子液体纯化Alq3：纯度和迁移率对OLED性能的影响

Alq3存在于5个晶相中，δ相中π轨道重叠最小，分子间结合距离短，具有良好的电荷输运特性。以前，Alq3的纯化是使用离子液体而不是升华方法来获得这种特定相的。通过控制浓度和温度，可以得到高纯度的δ相Alq3。在这项研究中，使用离子液体净化Alq3的有效性不是通过高效液相色谱测量，而是通过制造和表征有机发光器件（oled）来评估纯度和迁移率的提高。制备器件的I-V-L测量表明，净化后的阈值电压降低，最大亮度增加，亚阈值摆动减少。I-V特性证实了离子液体基净化在提高材料纯度方面的有效性。最后，制备了纯电子器件，并利用Mott-Gurney方程计算了电荷迁移率。将模拟结果与实验结果进行比较，阐明离子液体纯化δ相Alq3对OLED性能的影响。图形抽象

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Electronic Materials Letters 工程技术-材料科学：综合

CiteScore

4.70

自引率

20.80%

发文量

审稿时长

2.3 months

期刊介绍： Electronic Materials Letters is an official journal of the Korean Institute of Metals and Materials. It is a peer-reviewed international journal publishing print and online version. It covers all disciplines of research and technology in electronic materials. Emphasis is placed on science, engineering and applications of advanced materials, including electronic, magnetic, optical, organic, electrochemical, mechanical, and nanoscale materials. The aspects of synthesis and processing include thin films, nanostructures, self assembly, and bulk, all related to thermodynamics, kinetics and/or modeling.