Polymer light-emitting electrochemical cells: Recent developments to stabilize the p-i-n junction and explore novel device applications

Polymer light-emitting electrochemical cells (PLECs) employ a thin layer of a luminescent conjugated polymer admixed with an ionic source and an ionic conductor for the in-situ formation of p-i-n junction and subsequent efficient injections of both electrons and holes. The junction formation enables the use of air-stable conductors as the cathode and a relatively thick emissive polymer layer that is more compatible with low-cost solution-based processes. This paper overviews the operation mechanism of the PLECs, the properties and drawbacks of the devices. The employment of crosslinkable ionic conductors to stabilize the p-i-n junction is reviewed. The resulting static junction electroluminesces light at high brightness, high efficiency, and prolonged lifetime. Silver paste and carbon nanotubes can be used as the cathode, thus, PLECs were fabricated by lamination. Using single wall carbon nanotubes coated elastic substrate as both anode and cathode, the PLECs can be made highly stretchable.