The big picture: Among the three pixel colors of OLED displays, blue stands out for its inefficiency and shorter lifespan compared to red and green pixels. But now LG claims to have cracked this code using a combination of tandem OLEDs and a mix of blue phosphorescent and fluorescent materials. This innovation will lead to better efficiency and improved image stability over the life of the display.
LG made waves in 2012 when it released its first 55-inch OLED TV. OLED technology is known for its impressive picture quality and low response time compared to LCDs. However, it also has some drawbacks, such as high cost and image burn-in. Image burn-in occurs when static images (e.g. the Windows taskbar, news tickers, game HUDs) are displayed for long periods of time, causing pixels to decay faster and leaving behind “ghost images.”
Display manufacturers have developed several methods to prevent burn-in. These include dimming the pixels on static images to reduce pixel stress and pixel shifting, which shifts the pixels slightly at regular intervals.
One of the main factors for burn-in is the blue pixel and its light emission compared to red or green pixels. OLED pixels are made of organic material that emits light through either phosphorescence or fluorescence. Phosphorescence is generally more efficient and can degrade more slowly. Red and green pixels in some OLED technologies use phosphorescent emitters, while blue pixels typically emit light through less efficient fluorescence. Because blue pixels require more power to achieve a similar luminance as red and green pixels, they degrade more quickly, contributing to burn-in problems.
LG’s “Dream OLED” addresses this challenge by using a two-layer tandem structure in which the OLED light elements are stacked on top of each other. This stacked design uses both fluorescent and phosphorescent materials for blue light. LG estimates that Dream OLED enables a 10-20 percent increase in display efficiency. This efficiency increase reduces pixel stress and extends the lifespan of the blue pixels. Universal Display Corporation, a US-based display materials manufacturer, supplies the blue phosphorescent material.
See also: The OLED burn-in test: Intentional burn-in
Tandem OLED technology may sound familiar, as Apple introduced a similar concept in its 2024 iPad Pros. Apple’s approach is to stack two OLED layers on top of each other, which improves brightness and longevity but doesn’t directly solve the blue pixel problem. If LG’s efficiency estimates hold true, it’s not far-fetched to assume that phone makers could be the first to adopt this battery-saving feature.
So when can consumers expect to get their hands on Dream OLED? According to an industry official, “We plan to evaluate the performance for mass production within the year and consider commercialization.” While the public may have to wait at least another year or two to see the fruits of LG’s efforts, the future of OLED looks bright.
