What Is PHOLED?

PHOLED stands for Phosphorescent Organic Light-Emitting Diode—an OLED that uses phosphorescent emitters (typically heavy-metal complexes such as iridium(III)) to convert both singlet and triplet excitons into light. This “triplet harvesting” is why PHOLEDs can achieve ~100% internal quantum efficiency (in principle), versus ~25% for conventional fluorescent OLED emitters.

How PHOLEDs work (display-engineering view)

• In electrically driven OLEDs, excitons form with spin statistics of roughly 25% singlets / 75% triplets.
• Phosphorescent emitters use strong spin–orbit coupling (from the heavy metal center) to enable efficient emission from triplet states (phosphorescence), so triplets aren’t “wasted.”

Why PHOLED matters in products

• Higher efficiency / lower power for a given brightness (especially impactful for red/green subpixels and many lighting applications).
• PHOLED is also used as a commercial technology brand—for example, Universal Display Corporation markets and licenses UniversalPHOLED® materials/technology.

Key practical challenge (especially for blue)

• Blue PHOLED stability/lifetime has historically been harder than red/green due to higher excited-state energies and long triplet lifetimes that can accelerate degradation; this has been a major industry focus.

If you tell me whether your focus is mobile OLED (power), TV (luminance & lifetime), or lighting (efficacy & lifetime), I can translate PHOLED into the key design knobs (emitter selection, host, stack design, roll-off control, and lifetime drivers).