Light-Emitting Polymer Blended with Elastomers for Stretchable Polymer Light-Emitting Diodes

Intrinsically stretchable light-emitting diodes (LEDs) will be critical components in future stretchable electronics. However, limited research has been conducted on stretchable electroluminescent (EL) layers for LED devices. Blending conjugated polymers (CPs) with an elastomer has been a simple and effective method enabling widespread use of stretchable polymer semiconductors in stretchable field-effect transistors (FETs). In this study, we adopted the concept of blending elastomers into CPs for use in stretchable polymer LEDs (PLEDs). By blending light-emitting polymers prepared from polyphenylenevinylene (PPV) derivatives with thermoplastic polystyrene-block-polybutadiene-block-polystyrene (SBS) elastomers, a stretchable emission layer (EML) was fabricated, and its mechanical, electrical, and morphological properties were studied. The blended film was stretched up to 60% before vertical cracking occurred, and it maintained its pristine electrical properties. Finally, stretchable PLEDs were fabricated with the use of stretchable EMLs, and this showed that 50% of the maximum luminance was maintained upon stretching up to 60%.