Tandem OLED is OLED’s latest weapon in holding off MicroLED, QDEL

Tandem OLED has been around for years, but Apple made the technology feel new and shiny when it announced that the screen in its first ever OLED-based iPad would use a tandem structure.

Other consumer gadgets, like laptops and phones, are also slowly starting to incorporate Tandem OLED displays. So we thought it's a good time to look at how Tandem OLED is used, what benefits it's delivering, and how the technology could impact future devices and compete against other emerging display technologies, like MicroLED and QDEL.

OLED TVs, monitors already use different kinds of tandem stacks

We won’t go too deep into the technical details of Tandem OLED in this article (interested readers can reference this handy breakdown, which also includes information on current technical obstacles, like light-extraction inefficiencies). But if you're new to Tandem OLED, here’s a brief look at what makes it so interesting for tech gadgets.

Simply put, Tandem OLED screens, like the one on the M4 iPad Pro, have two layers of red, green, and blue (RGB) organic light-emitting layers stacked atop one another and are driven in tandem. Because of those two layers, a Tandem OLED screen can reach the same brightness levels as an identical design with one OLED stack but with each layer in the display running at lower currents than in a single-stack OLED. The primary benefits are less burn-in risk, less power consumption, and the potential for higher brightness levels.

In this article, we'll use the term "Tandem OLED" to refer to displays that use two layers of RGB OLED materials. This is the setup that has received recent attention in consumer displays thanks to devices like the iPad Pro and XPS 13. But other OLED displays use different kinds of tandem structures. OLED TVs and monitors using LG Display's WOLED (white OLED) and Samsung Display's QD-OLED (quantum dot OLED) also use tandem stacks.

QD-OLED screens even use three stacks of blue OLED emitter layers (reportedly to manage the inefficiency of blue emitters).

As Ross Young, CEO at Display Supply Chain Consultants (DSCC), told me via email, "WOLED uses two blue layers with red and green in a stack, and QD-OLED uses three blue layers and green in a stack. These panels are creating white (WOLED) and blue (QD-OLED) light only, so it is different than the RGB tandem stacks being used for the OLED iPad Pros and select automotive displays."

With modern OLED TVs already getting a lot of brightness from their current multi-stack OLED architectures, there may be minimal incentive for Tandem RGB OLED stacks to hit high-end TVs, Eric Virey, principal displays analyst at Yole Intelligence, told me. He also noted complications in the manufacturing process:

In addition, the manufacturing process used in TV manufacturing is different from the one used in smaller OLED devices and wouldn’t be compatible with RGB Tandem OLED. To be more specific, small OLED displays, such as smartphones, tablets, smartwatches, and laptops, are made using a Fine Metal Mask (FMM) patterning technology, whereas large OLEDs, such as TVs, use an open mask. The latter wouldn’t fly with an RGB Tandem OLED architecture.

Some common misconceptions

Before diving into what Tandem OLED can do, let's quickly address some common misconceptions about the technology.

One is that Tandem OLED devices have "two OLED screens." When Apple announced the OLED-based iPad Pro in May, it said the tablet "uses two OLED panels and combines the light from both to provide phenomenal full-screen brightness." But technically, Tandem OLED devices use multiple stacks of organic emitting materials within one screen or display. As LG Display explained in a 2023 blog post about Tandem OLED in automobile displays, “by harnessing two organic emitting layers, it delivers brighter screens while effectively dispersing energy across the OLED components for optimal stability and a longer lifespan.”

Another misconception is that Tandem OLED is a brand-new technology. While adoption is growing, the tech has been around for years—LG Display introduced Tandem OLED in 2019 for displays in cars. And despite some reports that the 2024 iPad Pro has the "first-ever tandem OLED display," the Honor Magic 6 RSR Porsche Design came out months earlier with a Tandem OLED structure.

Tandem OLED offers multiple paths for improving OLED devices

One of the most exciting things about Tandem OLED is that it can address some of the biggest drawbacks associated with OLED, namely around brightness, energy consumption, and lifetime. Virey points out that because the two OLED stacks in Tandem OLED structures can each work less hard, OEMs can decide which trade-offs they want to make. Per Virey, the stack can:

• Generate twice as much light with same current density
• Generate the same amount of light but with only half the current going through each stack
• Reduce the power consumption for the same brightness
• Increase the lifetime and reduce burn-in.

The Tandem OLED gadgets currently available illustrate how different implementations leverage different benefits of the technology.

The iPad Pro's implementation, for example, targets brightness. Since the M4 tablet is Apple's first OLED tablet, we can't make an apples-to-apples comparison. However, it's impressive that the 2024 iPad Pro has a higher SDR brightness claim than the preceding Mini LED iPad Pro from 2022 (1,000 nits versus 600 nits).

This differs from the XPS 13, which also uses Tandem OLED but isn't marketed as being significantly brighter than XPS 13s using non-Tandem OLED (its 482-nit claim is on the higher end for an OLED laptop, though). Instead, the thin-and-light laptop uses Tandem OLED to extend battery life by up to 10 percent, Alyssa Degregorio, XPS product planner at Dell, told me.

Meanwhile, automotive displays use Tandem OLED for brightness (helpful for visibility to drivers) and longevity (essential for cars expected to last for years). And Honor used Tandem OLED for durability. When announcing its Tandem OLED smartphone, Honor claimed "an extended screen lifespan of up to 600 percent" and said that using Tandem OLED reduced "display brightness degradation to less than 1 percent after three years of use" while providing "brighter visuals and improved power efficiency."

Tandem OLED and burn-in risk

Depending on the type of gadget, it can make less sense for an OEM to use the max brightness capability of a Tandem OLED display because it can lead to greater burn-in risk. As Virey noted, burn-in is a bigger concern for laptops than tablets:

Tablets are often used a few hours a day with content, such as video or picture, that have a low average picture level (only 20–30 percent of the pixel [is] on at any time).

 

Laptops can run nonstop for 8–10 hours a day, often on productivity applications, which means that essentially all pixels are lit up almost 100 percent of the time (white background—think Excel, Word, etc.). This [leads] to shorter lifetime, burn-in issues, etc.

Tandem OLED can lower burn-in risk by "reducing the intensity and duration of stress on a single layer," Ross explained. Since the two RGB stacks share the burden of light generation, each stack receives about half the current as a single-stack OLED, meaning OLED materials are less strained, resulting in slower degradation.

In addition to LG Display, other suppliers, like TCL China Star Optoelectronics Technology (TCL CSOT), are working on Tandem OLED offerings with greater durability. As usual, tech companies' spec claims should be taken with a grain of salt. But at CES 2024, TCL CSOT demoed a 14-inch Tandem OLED screen it said would last 3.5 times longer than standard OLEDs.

Since Tandem OLED can help make displays last longer, they would seem to be an obvious fit for PC monitors, which are typically more prone to burn-in than other gadget types, largely because of how they're used. Analysts I spoke with think it will be a few years before OLED computer monitors will sport tandem RGB stacks—if they ever do.

"We may see some attempt at dual stack RGB OLEDs for monitors when new G8.7 OLED fabs come online using fine metal masks in 2026–2028," Ross said. "There is also a significant effort under way at Visionox, JDI, and others to pattern OLEDs without fine metal masks and to use photolithography instead. They are not looking at monitors and TVs for their initial applications, but perhaps in the future. They are also looking at G8.7 fabs, which are more conducive to making larger panels."

Virey agreed that Tandem OLED may make its way to high-end PC monitors eventually. "Many new generations of OLED fabs geared toward IT products are currently being built by Samsung Display, BOE, and possibly later on by Visionox, LG, and others," he said. "Those will initially target tablets, notebooks, and probably automotive, but it’s probable that [as] they mature, desktop monitors will become a target as well."

Brighter OLED

One of OLED's most-discussed disadvantages compared to quality LCD-LED alternatives is its lack of comparative brightness. OLED fans might argue that OLED's deep, inky blacks and superior contrast mean that this limitation has minimal impact on overall image quality and users' experiences.

But in various situations—such as in sunny offices, well-lit living rooms, outdoors, or in other setups where a screen can't avoid being cast in ambient light—dimmer displays can be distracting. Plus, for better or worse, tech shoppers tend to use specs and pricing for product comparisons. Those are two areas where LCDs typically beat OLED, giving OLED device makers plenty of incentive to get more nits on their OLED gadgets' spec sheets.

LG Display says it is mass-producing 13-inch Tandem OLED screens for laptops that have "triple the brightness of a conventional single-layer OLED display." It will be up to OEMs to decide if they want to use this capability or only focus on power consumption and/or durability.

LG is also reportedly planning to mass-produce third-generation Tandem OLEDs for cars in 2026. Business Korea's sources claimed in July that the displays will improve brightness and power consumption by 20 percent compared to the second generation. And the aforementioned Tandem OLED display that TCL CSOT demoed in January claimed a peak brightness of about 2,500 nits.

Despite tandem OLED's potential for boosting brightness, its adoption probably won't have a big impact on HDR viewing. The peak brightness supported by HDR standards like Dolby Vision, HDR10, and HDR10+ is technically 10,000 nits (Grand Turismo 7 hits this), but the vast majority of HDR content is mastered at a maximum of 1,000 nits. With the iPad Pro, Tandem OLED has already proven it can reach 1,600-nit HDR highlights in real products. And while some companies (like Sony) are looking to make 4,000 nits more common among HDR content, there are obstacles, including filmmaker preferences and the existence of limited, capable reference monitors and TVs.

Although higher peak luminance from Tandem OLED would technically improve contrast ratios, Virey thinks that wouldn't affect HDR viewing much.

"Yes, doubling the brightness will indeed double your contrast," he said. "The improvement will definitely be measurable in a lab, but OLEDs are already so good with their inky blacks that I’m not expecting much of a difference in term[s] of the consumer experience."

Tandem OLED development and adoption still has a long way to go before it's considered an equally bright alternative to LCDs. Further, a brighter screen doesn't automatically make one display superior to the other. Many OLED adopters are already satisfied with the brightness capabilities of premium OLED displays, so a greater focus might be put into making OLED devices like laptops and tablets more energy-efficient. With these types of gadgets, battery life could be a bigger consideration for users than a display's max brightness.

OLED gadgets with better battery life

OLED gadgets tend to be power-hungry. But because Tandem OLED displays can produce more light with a given amount of electric current than single-stack alternatives, they can also excel at battery conservation. The iPad Pro, for example, has the same battery life claim as the preceding Mini LED version despite having a brighter OLED display and a more powerful processor.

OLED has become popular among laptops, especially expensive ultralights. But with such systems also having minimal physical room for battery packs, one of the biggest concerns about premium, thin OLED laptops is low battery life—a large downside, of course, because these PCs are designed for portability.

Dell's latest XPS 13 shows how Tandem OLED can address this limitation. The Tandem OLED-based XPS isn't brighter than the prior, standard-OLED XPS 13. Instead, the use of Tandem OLED is about improving battery life, Dell's Degregorio, told me.

"Because OLEDs generally consume more power than traditional LCD panels, minimizing power consumption is crucial," she said. "The XPS 13's new Tandem OLED design lowers power consumption for the same brightness compared to the older single-stack OLED, which helps extend battery life. This new design, combined with Tandem technology, improves battery runtime by about 10 percent, while also being... approximately 3 percent thinner and 5 percent lighter than the previous generation with its older OLED."

As mentioned above, LG Display is mass-producing 13-inch Tandem OLED laptop displays that it claims can be three times brighter than its typical laptop OLED. But more appealing for laptops, perhaps, are claims that the new displays can reduce power consumption by up to 40 percent.

The 13-inch panels are also supposed to be about 40 percent thinner than "existing OLED laptop screens," which leaves more room for the battery. Finally, LG Display claims that the new screens are 28 percent lighter, meaning OEMs could potentially fit bigger battery packs without making the laptop too heavy. LG Display claimed it was able to make its Tandem OLED laptop displays thinner and lighter "by designing the components and enhancing the structure" of the panels.

Looking ahead, suppliers are trying to expand the battery-related benefits of Tandem OLED. The display that TCL CSOT demoed in January, for example, claimed a 30 percent reduction in power consumption compared to standard OLED. In addition to the 2,500-nit peak brightness claim, the demo display ran 4K at 120 Hz, according to TCL CSOT.

Already an impact

Tandem OLED has already made an impact.

People had been seriously expecting Apple to release an OLED tablet since at least 2021, but it wasn't until the tandem architecture was ready that it became a viable Apple product. As Ross told the Society for Information Display (SID) in late 2023, “the thought was that Apple wouldn't even be doing an iPad with OLED unless these tandem stacks were something that was available."

"Because iPads and notebooks tend to have a white background on a lot of the applications, that would use a lot more power for OLEDs inherently and likely lead to faster burn-in. But with a tandem stack, it pushes all that out and makes OLEDs much more usable in IT applications,” he continued.

Some analysts expect Tandem OLED to impact phones. Honor kicked things off in March with the Magic 6 RSR Porsche Design. The smartphone's Tandem OLED display reportedly comes from BOE. The phone wasn't officially released in the US, but it represented a milestone for the technology's role in consumer devices.

When Honor announced the phone in March, however, DSCC cited unnamed supply chain sources and said that "no other smartphone brand or panel supplier has smartphones with Tandem OLED stacks on their roadmaps."

“Our take is that Tandem OLED stacks are better suited for IT applications where lifetime, power efficiency, and brightness efficiency are more important, given the amount of time people spend in front of a monitor, tablet, and notebook PC," DSCC said in a blog post. The blog also cited sources saying that BOE could be waiting to start mass production on OLED stacks for phones in 2026.

TCL CSOT, meanwhile, has been developing Tandem OLED displays for smartphones, including a 6.9-inch, foldable AMOLED that the company claimed hit 2,200 nits. TCL CSOT demoed it in May, saying that combined with a polarizer-free design, the Tandem OLED screen showed a nearly 50 percent reduction in power consumption. Additionally, TCL CSOT previewed a 7.85-inch "trifold" smartphone display with Tandem OLED tech.

Continuing with the unique form factor theme, TCL CSOT has also demoed a 14-inch, 4K slidable Tandem OLED screen this year that looks like it targets laptops. We can expect more R&D efforts looking to apply Tandem OLED to new and standout form factors. But we'll see how much such designs take off, especially considering the likely high costs and niche use cases. For now, you can check out the demo displays courtesy of OLED-Info below, starting at the 0:53 mark.

TCL CSOT shows its latest OLED, MicroLED and QD-EL displays at Displayweek 2024.

Holding off MicroLED and other advanced display tech

At this point, it's hard to predict which display technology will emerge as the next big thing for consumer devices. Tandem OLED is already starting to make an impact, but there's also plenty of interest in other advanced and developing display technologies, like QDEL, or backlight-free quantum dot electroluminescent displays and MicroLED.

Display enthusiasts have been eagerly anticipating QDEL, and especially MicroLED, for years. But Tandem OLED's successful implementation in some popular consumer gadgets makes it hard for other display technologies to usurp OLED.

Virey described OLED as "a moving target" for other emerging display technologies, like MicroLED and QDEL, adding that "Tandem OLED is just moving that target a little bit further."

Ross agreed that Tandem OLED's ability to boost brightness and efficiency reduces the need to move to other display tech, like pricey MicroLED and QDEL, which he said has "lifetime issues to overcome but may have a cost advantage."

As you might expect with new display tech, though, cost is a major obstacle to greater Tandem OLED adoption. Apple is a good illustration of this, Virey said, saying that it's expected that Apple will use single-stack OLED for OLED-based iPad Airs or iPad Minis (Apple hasn't publicly confirmed such devices).

I also asked Virey about how Tandem OLED might compete with PHOLED, or phosphorescent OLED, and the analyst said he doesn't view the technologies as competitors. Today's OLED gadgets already use red and green phosphorescent OLED, but blue phosphorescent OLED has been elusive. LG Display has reportedly made recent developments in this area, though.

"Once blue PHOLED finally becomes available in 2025 or 2026, most display makers will integrate them in their OLED displays (single or tandem) and deliver further improvement in lifetime, brightness, and efficiency," Virey said.

With Tandem OLED, MicroLED, and QDEL all limited to production costs and scaling challenges, some technologies may prove more popular with certain gadget types than others. For example, one interesting potential future application to consider is virtual and/or augmented reality. This summer, South Korean publication Sisa Journal reported that LG Display and Samsung Display are working on Tandem Micro OLED. When asked about the implications of this, Virey said tandem structures could help reduce motion artifacts and potential nausea by enabling brighter VR screens. For AR, however, Micro LED "will likely win," according to Virey.

"For AR glasses, when the display competes directly with outdoor light and the image is being delivered through very inefficient optics, the display brightness must be in the hundreds of thousands or even millions of nits of brightness. No amount of material stacks will get you there with OLED," Virey said.

As it stands, though, Tandem OLED is already starting to make waves among several device categories and with some big names in tech. OLED is also already a popular category among tech enthusiasts, so there's a good chance we'll see more Tandem OLED gadgets released in the near future.