UNIVERSITY of CALIFORNIA, SANTA BARBARA

Polymer light-emitting devices have historically been divided into two general types: polymer light-emitting diodes (PLEDs) and polymer light-emitting electrochemical cells (PLECs). PLEDs are advantageous due to their fast response time and relatively long operating life if properly packaged. PLEDs do, however, require low work function cathodes and interfacial layers between the metal and emitting polymer layer. However, PLECs have relatively low turn-on voltages and do not require low work function metals but have a slow response time compared to PLEDs. Unlike PLEDs,  PLECs possess mobile ions inside the polymer. PLEC systems of this nature involve two-component phase separation between the light-emitting polymer and the mobile ions. Phase separation attributed to poor compatibility between ionic materials and light-emitting polymers appears to degrade device performance and lifetime of the device.

Researchers at the University of California, Santa Barbara have created a hybrid polymer light-emitting device that combines the advantageous characteristics of PLEDs and PLECs. The novel technology comprises a soluble mixture of light-emitting polymers and a soluble ionic liquid. The novel copolymer acts as the light-emitting polymer and an ionic liquid is used to introduce mobile ions in the emitting polymer layer. Hybrid polymer devices exhibit excellent current-rectification diode properties, short response times, a single-phase active layer, and a long operating life.

•    Optoelectronic materials and devices

Categorized As

• Energy
  • Lighting
  • Other
• Optics and Photonics
  • All Optics and Photonics

Related cases

2007-079-0

Keywords

PLEC