Pioneering non-doped white light-emitting electrochemical cells utilizing pyridylimidazole-based copper complexes

• Published in: Dyes and pigments Vol. 231; p. 112384
• Main Authors: Yu, Zong-Cian, Shen, Hsiang-Ling, Chen, Shih-Jie, Wu, Hung-Yin, Lu, Chin-Wei, Su, Hai-Ching
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2024
• Subjects: 2-(2′-pyridyl)imidazole; Copper; Light-emitting electrochemical cells; Non-doped; White light; White light; Copper; Light-emitting electrochemical cells; Non-doped; 2-(2′-pyridyl)imidazole
• ISSN: 0143-7208
• DOI: 10.1016/j.dyepig.2024.112384

Light-emitting electrochemical cells (LECs) hold potential for low-cost, large-area lighting applications due to their air-stable electrodes and various solution preparation methods. However, the high cost of noble metals poses a significant challenge to the development of LECs. To address this issue, this study designed a series of five copper(I) complexes within the framework of using 2-(2′-pyridyl)imidazole (PI) as a ligand to achieve efficient copper-based ionic transition metal complexes (iTMCs). In electroluminescence (EL) tests of LECs, complexes Cu-PI-P and Cu-PI-PFCN exhibited the highest efficiency of saturated red emission to date, with maximum external quantum efficiencies (EQE) of 0.63 and 0.82 %, respectively. Additionally, Cu-PI-PCN, Cu-PI-PFCN, and Cu-PI-PF are the first white-light emitting LECs known in the literature using a non-doped approach, with EQE of 0.34, 0.43, and 0.98 %, respectively. •Five copper(I) complexes using 2-(2'-pyridyl)imidazole to achieve efficient copper-based ionic transition metal complexes.•Complexes Cu-PI-P and Cu-PI-PFCN exhibited the highest efficiency of saturated red emission to date.•Cu-PI-PCN, Cu-PI-PFCN, and Cu-PI-PF are the first white LECs known in the literature using a non-doped approach.