tandem architecture - Page 4

Researchers from South China University of Technology and Guangzhou New Vision Opto-Electronic have found that the lifetime and current efficiency of a tandem OLED device can be greatly improved by adding an ultra-thin Ytterbium (Yb) metal layer through the charge generation layer (CGL).

The experiments detail an ultra-thin Yb metal layer with low work function, high transmittance, and large atomic radii, added to a light-green tandem OLED devices. The new device exhibited a lifetime of 308 hours (T90) at an initial brightness of 10,000 cd/m² - which is 362 times (!) longer than that of a similar device without the Yb layer (T90 = 0.85 hours). The lifetime of the same material in a single-layer configuration (not a tandem device) was 49 hours (T90).

LG Display is demonstrating its new 30" and 77" transparent OLED displays for the first time, at the company's booth at K-Display 2023, in Seoul, Korea.

Credit: LG Display

The new 30" transparent OLED offers HD resolution, while the 77" panel offers 4K resolution. All of LG's latest transparent OLED displays offer 45% transparency. LG showed its entire range of T-OLED displays in a coffee shop setting, in partnership with Starbucks.

eMagin announced that it developed (and demonstrated) a 15,000 nits WUXGA (1920x1200) full-color OLED microdisplay, setting a new world record (surpassing eMagin's own 10,000 nits record from 2021).

This new microdisplay was deposited using the company's direct-patterning (dPd) technology, which means that there are no color filters. This is a single-stack device, and eMagin says that in the future it could use a tandem architecture to improve the performance further.

Apple's interest in OLED displays for future iPad tablet device is not secret, and many analysts estimate that the first such device will be released in 2024.

One of Apple's requirement is for superior performance for its tablets compared to smartphone AMOLED displays - and so developers are relying on a tandem OLED structure. According to a new report from Korea, LG Display is developing another unique technology for Apple's iPads.

DSCC says that even though the display market is facing difficult market conditions, the automotive displays segment is expected to continue growing, and total shipments (both LCDs and OLEDs) are expected to exceed 200 million panels (an average of over 2 displays per car).

OLEDs are still a small percentage of the market (less than 0.5%, in fact), but OLEDs will gradually penetrate high-end applications for flagship models, as OLED makers adopt flexible and tandem-architecture technologies.

Korea-based ETNews reports that Apple has finally committed to adopt OLED displays in future tablets and laptops, and the company has signed a contact with a "local OLED developer" (which means either Samsung Display or LG Dispaly) to develop four different OLED displays.

According to the report, Apple decided to adopt a 10.86" and 12.9" AMOLED displays for future iPad devices, and 14" and 16" displays for future MacBooks. The first OLED iPad will be released in 2024, while the first OLED MacBook will come later in 2026.

In the past year or so, much have been said about Samsung's plans to build a 8-Gen OLED IT production line, as the company wants to expand its capacity for monitors, laptops and tablet OLED displays.

Samsung plan for a full-cut 8-Gen line

As this is the first such production line, SDC had two ongoing R&D projects: one with Ulvac, that used full-cut vertical OLED deposition, and another with Canon Tokki, that used half-cut horizontal deposition. According to the latest reports from Korea, SDC decided to prioritize the Canon Tokki half-cut project, as the technology is more mature and is more likely to finish as per Apple's roadmap.

KT&T, established in 2020 as a spin-off from INT Tech with an investment of $143 million, has developed an OLED microdisplay that achieved a brightness of 12,000 nits, which is the highest brightness OLED microdisplay ever developed.

The new panel is based on KT&T's own uNEEDXR technology, which is a direct-emission (no color filters) design. The display achieves very high brightness and high efficiency.

According to UBI Research, Samsung Display has decided to produce QD-OLED panels at its upcoming 8.7-Gen A5 production line. The company IT display strategy will be to produce QD-OLED panels for monitor application (27-inch displays, at first) and tandem RGB panels for smaller IT displays (tablets, laptops).

A 34-inch QD-OLED monitor (Dell Alienware)

Samsung is looking for design wins with Apple for both its display architectures - the larger QD-OLED panels for Apple's monitors and the smaller sized panels for its tablets.

Last Month Samsung Display confirmed that Samsung is now building a 8-Gen (2200x2500 mm) OLED production line, that will begin production in 2024.

It is expected that the new line will mostly produce panels for IT devices (laptops and tablest) and also for automotive applications. Many believe that these applications will adopt tandem stack structure to increase brightness and lifetime. According to a new report, Samsung's new line will adopt a single-stack structure, and not a dual-stack one.