Fundamentals of Materials Selection for Light‐Emitting Electrochemical Cells. (20th March 2020)

• Record Type: Journal Article
• Authors: Youssef, Kareem; Li, Ying; O'Keeffe, Samantha; Li, Lu; Pei, Qibing
• Is Part Of: Advanced functional materials. Volume 30:Number 33(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-03-20
• Subjects: electroluminescence -- electrolytes -- light‐emitting conjugated polymers -- light‐emitting electrochemical cells -- p–i–n junction formation; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201909102
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: The in situ formation of a light‐emitting p–n or p–i–n junction in light‐emitting electrochemical cells (LECs) necessitates mixed ionic–electronic conductors in the active layer. This unique characteristic requires electronic, luminescent, and ionic ingredients that work synergistically in the LECs. The material requirements that lead to promising electroluminescent properties are discussed and the important components reported so far are surveyed. Particular attention is paid to the working mechanisms behind junction formation and stabilization to create efficient and stable electroluminescence in conjugated‐polymer‐based LECs. Keeping these fundamentals in mind explains how LEC devices have evolved from classic conjugated polymer blends into highly stable crosslinked, hybrid composite, and stretchable device architectures. To conclude, a future development strategy is proposed based on a dual approach: develop new materials specifically for LEC devices and explore novel ways to efficiently process and stabilize the p–i–n junction, which will drive improvements in both LEC external quantum efficiency and operating lifetime toward truly low‐cost solid‐state lighting applications. Abstract : A metastable p–i–n junction is the key mechanism to form light‐emitting electrochemical cells, a simple and single layer light‐emitting device. However, designing a mixed ionic–electronically active material requires judicious materials selection and processing to ensure efficient, stable electroluminescence. An introduction to the field, key materials, mechanisms, and recommendations to move the research forward is presented.