OLED

An organic light-emitting diode (OLED) is a light source in which the light comes from thin layers of carbon-based, or organic, semiconductor material placed between two electrodes. When electricity flows through the layers they glow. OLEDs are used to make display screens for phones and televisions, and as thin, flexible panels for lighting. They are related to ordinary LEDs, but they are built from different materials and give off light across a surface rather than from a point.

History of OLEDs

Scientists first observed organic electroluminescence, the emission of light from an organic material carrying a current, in the 1960s. The materials supplier Ossila reports that researchers at New York University found in the early 1960s that the dye anthracene could glow when a high voltage was applied. Practical devices were held back by the high voltage needed to push charges into organic crystals and by uncertainty about how long the diodes would last. Meanwhile, researchers found that some organic materials fluoresce very efficiently across the visible spectrum, including blue, with quantum efficiencies approaching 100 percent, so the potential was clear once the voltage problem was solved.

The breakthrough came in 1987 from Ching Tang and Steven Van Slyke at the Eastman Kodak Company. Their paper, “Organic electroluminescent diodes,” appeared in the journal Applied Physics Letters on 21 September 1987. By combining modern thin-film deposition with suitable materials in a double-layer structure, they built a device that worked at a low operating voltage.

Since then the design has grown from that simple two-layer structure into more complex, multi-layered stacks that raise efficiency. The first generation of emitters used fluorescence. A second generation added heavy metals such as iridium to the emitting layer, producing phosphorescence, which greatly improved efficiency.

How OLEDs work

The U.S. Department of Energy (DOE) describes an OLED as a solid-state device, meaning it has no moving parts or glass bulb, built around a thin carbon-based semiconductor layer. Electrodes on either side apply a current, and at least one of the electrodes must be transparent so that light can escape. The brightness depends on how much current is applied, and the color depends on the type of emissive material used. To create white light, most devices combine red, green and blue emitters in one of several arrangements.

In a display, small OLED elements can be arranged as pixels that each produce their own light. This is the main structural difference from a liquid crystal display, which has to shine light from a backlight through a layer that only controls how much passes.

Types of OLEDs

OLEDs are commonly sorted by purpose. Display OLEDs are made of many small pixels and appear in phones and televisions. Lighting OLEDs are made as larger panels, which the DOE calls the light-emitting devices used to build a luminaire, or complete light fixture. Panels can be rigid or built on flexible substrates, and they can be made transparent so that light comes out of both sides.

They can also be grouped by the emitter chemistry used inside, from the early fluorescent molecules to the phosphorescent designs that followed. Each choice trades efficiency, color purity, lifetime and cost against the others.

Applications of OLEDs

Smartphones are among the most familiar uses, and OLEDs are still described as an emerging technology despite being conceived more than three decades ago. For lighting, the DOE reports commercial panels with an efficacy of 85 lumens per watt and a color rendering index above 90, a measure of how faithfully a light shows colors. Bendable panels with more than 60 lumens per watt are also on sale.

Because OLED light is soft and diffuse, it can be viewed directly without shades, diffusers or lenses, and it can be placed close to a work surface without producing glare. This opens design possibilities such as thin sheets mounted on walls and ceilings.

Advantages and disadvantages of OLEDs

OLEDs can be extremely thin, shaped almost freely and deposited on flexible material. They offer an energy-saving potential similar to that of LEDs, according to the DOE, and their light is gentle on the eye. In displays, the light comes from the pixels themselves, which suits thin screens.

The limits are mostly cost and durability. Lifetime is improving. The DOE says many panel products expect 30,000 to 50,000 hours of use before the light output falls to 70 percent of its starting value. Cost remains the main obstacle: a panel currently costs around $100 per kilolumen, and the DOE projects that OLED lighting needs panel costs near $10 per kilolumen to become commercially viable. As a result, the agency says OLEDs are still some years from widespread use for general illumination. Early researchers also cited the unknown long-term stability of organic diodes as a key concern, and lifetime still shapes how products are designed.

OLED vs. LED and LCD

The DOE draws a clear line between OLED and LED lighting. LEDs are small, intense point sources, while OLEDs are made in sheets and give diffuse, area light. Compared with an LCD, an OLED display makes its own light instead of filtering light from behind. Both OLED and LCD screens are common in consumer products, and the best choice depends on cost, brightness, lifetime and thickness. Liquid crystal displays remain widely used, while OLED panels are favored where thinness and flexibility matter most.

Future of OLEDs

The DOE describes OLEDs for general illumination as being at a critical stage. Panels with high brightness allow smaller devices to reach the same light output, and lifetime and efficacy keep improving. Whether OLED lighting spreads widely will depend on whether production costs fall by roughly a factor of ten, a gap the agency identifies as the central challenge for the technology.

Editorially reviewed by Specialty Digest Editorial TeamLast reviewed November 4, 2026Researched and drafted with AI assistanceReport an issue