tandem architecture

In 2022, Japan Display (JDI) announced that it has developed a "historic breakthrough in display technology" - a new OLED deposition process which they refer to as eLEAP, that is said to be cost effective and can be used to create freeform OLEDs that are brighter, more efficient, and longer lasting compared to OLEDs produced using mask evaporation (FMM).

JDI is planning to establish a 8.7-Gen eLEAP fab in China, and it is also building a smaller-scale 6-Gen eLEAP production line in Mobara, Japan. The company announced that the 6-Gen Mobara fab is advancing ahead of schedule, and production of eLEAP panels will begin before the end of 2024. JDI developed 14" laptop panels that are three times brighter than other OLEDs (at 1,600 nits), and is also targeting smartwatches, smartphones and automotive displays. JDI is also looking into adopting a tandem structure, to increase brightness even further to 3,000 nits.

In January 2024 we reported that Samsung Display and LG Display have started to produce AMOLED displays for Apple's future iPads, to be announced later this year. Earlier expectations were for Apple to order a total of 10 million iPad AMOLED displays in 2024 from both LGD and SDC, with LGD getting around 60% of the orders. 

Apple was aiming to launch the new OLED iPads this month, but have now reportedly delayed the release to May, as Samsung is suffering from low yields for the 11" AMOLED panels, mostly due to the tandem stack architecture.

OLED lighting developer OLEDWorks announced that it has been awarded a $8.6 million US army project to develop high-performance OLED microdisplays for consumer and defense applications. The display is targeted specifically towards head-mounted display applications in the AR and VR markets.

OLEDWorks says that its microdisplay platform offers high brightness, full color, and excellent lifetime. The company says that it is developing three OLED microdisplay products. The company's displays are based on OLEDWorks' proprietary multi-stack (3, 4, and 5-stacks) OLED technology to OLED microdisplays.

According to reports, BOE has commercialized a new tandem OLED architecture, that enabled an improvement of 40% in power consumption and a 600% increase in display lifetime. 

As you can see from the teaser poster above, Chinese smartphone maker Honor will release the first phone to adopt the new panel, the Honor Magic 6 Ultimate, next week on March 18th.

LG Display announced that its automotive OLED displays (both its flexible P-OLED panels and its rigid ATO panels) received TÜV Rheinland’s ‘Product Carbon Footprint’ certification, a milestone marking compliance with emissions standards across the product’s lifecycle. LGD's automotive OLEDs are highly efficient, and both utilize the company's tandem OLED structure.

LGD says that it recently introduced a new film to its automotive OLEDs, developed in-house, "Light Control Film Integration Technology" that enabled it to reduce its automotive OLEDs carbon emissions by up to 18% compared to its previous OLEDs.  This method also has the added benefit of effectively streamlining the manufacturing process, further reducing product weight, and improving power efficiency compared to conventional panels that use external films.

Reports from Korea suggest that Samsung Display and LG Display are starting to produce AMOLED displays for Apple's future iPads, to be announced later this year. Samsung is set to produce 11" LTPO AMOLED displays, while LG Display is producing displays for the 13" model (but LGD will also produce 11" AMOLEDs in the future for Apple). 

The Elec says that both Korean makers developer 11" and 13" displays, but for some unknown reason only LGD will produce the 13" displays. This could change in the future, of course. One reason could be that LG Display has more experience with tandem OLED architectures (developed originally by LGD years ago for automotive OLEDs).

TCL is demonstrating a new 14" 4K 120Hz flexible AMOLED display that adopts a tandem display structure. The tandem structures enabled a reduction in power consumption of over 30%, an extension of the display's lifetime (3.5X) and a peak brightness of over 2,500 nites.

TCL was also showing a new 6.36" 1200x2670 LTPO AMOLED display, that features the company's new frequency division technology and self-developed frequency scanning circuits. Coupled with an ultra-low power consumption IC, it offers 15-20% power savings compared to TCL's standard AMOLEDs. 

DSCC estimates that the market for OLED evaporation materials (i.e. OLED stack materials) will reach $1.7 billion in 2023, and will grow to $2.7 billion in 2027 (a 11% CAGR from 2023). If UDC will succeed to commercially introduce a blue phosphorescence material, revenues can even be much higher.

OLED materials used in TV applications (and other large-area applications) will grow from $305 million in 2023, to $492 million in 2027, a 13% CAGR. DSCC also sees very fast growth in material used to produce tandem-structure IT displays, which will grow at a 79% CAGR to reach $443 million in 2027.

OLED microdisplay maker Sidtek announced that it is starting to install production equipment at its 12-inch production line in Wuhu City, Anhui Province. The company says the first production line in the project is on track to start production in 2024.

Sidtek is currently producing its OLED microdisplays on a 8-inch production line, also in Wuhu. The first phase of its 12-inch fab will have a monthly capacity of 6,000 substrates, and the company is planning an expansion to 18,000 substrate. The total investment in the 12-inch fab (including the 2nd stage) is estimated at 6 billion Yuan (around $840 million USD).

LG Display announced that it has started to mass produce 17" 2560x1920 foldable OLED laptop displays. LGD applied a tandem stack architecture, to increase the lifetime of the OLED displays, to make it suitable for the demands of laptop use.

It is likely that the recently announced HP Spectre Foldable PC uses LG's new panels.