PLEDs use semiconducting polymers that emit light when electric current is applied. They provide more efficient LED displays than traditional LEDs, and are useful for portable device displays due to their flexibility and thinness. PLEDs have an anode, cathode, and polymer film sandwiched between them. When voltage is applied, the polymer emits light. PLEDs can be flexible, transparent, or stacked to provide different display types and colors. They have advantages over LCDs like lower power use and wider viewing angles, but shorter lifetimes. PLEDs are being developed for applications like phones, watches, TVs, and more.