Advanced Functional Materials: Special Issue: 25 Years of Light‐Emitting Electrochemical Cell Technology

The operation of polymer light‐emitting electrochemical cells requires electronic, luminescent, and ionic ingredients that work synergistically in the devices. In article number 1909102, Lu Li, Qibing Pei, and co‐workers discuss the mechanisms behind the junction formation and stabilization to create efficient and stable electroluminescence. How the light‐emitting electrochemical cell devices have evolved from classic conjugated polymer blends into stable, crosslinked, hybrid composite, and stretchable device architectures is also presented.