Power consumption

LG Display says that it has started to mass produce tandem OLED laptop panels, the first company to do so. LGD says its tandem architecture double the lifetime of its OLEDs, reduce power consumption by up to 40%, and enable up to three times the brightness.

LGD has been producing tandem OLED displays since 2019, mainly for the automotive industry. This expertise has enabled it to be Apple's main tandem OLED display suppler for its 2024 iPad Pro devices, and now to be the first one to produce tandem laptop panels. 

BOE had a large demonstration at Displayweek 2024, showing several display technologies and many new panels and prototypes.

First up we have a slidable OLED display, one of the largest we've seen, at 31.6". The display offers a resolution of 5944x1672, a sliding distance of just over 260 mm (BOE says its the world's longest) and a sliding radius of 5 mm.

The display industry's premier event, Displayweek, is over. We will now collect our notes, thoughts, photos and images and will share it all in the coming days. In the meantime, we'd like to detail some initial impressions.

Generally speaking, it seems as if the display industry is going through a phase of relatively little innovation, especially with the mature LCD and OLED industry segments. While it has been a very busy week, and attendance at the event seems high, the number of actual demonstrations and prototypes was not stellar and compared to previous years, the booths were smaller and some companies skipped the event this year or preferred to only show their latest displays in private settings. Some thoughts we have:

In 2014 Konica Minolta started constructing its groundbreaking R2R flexible OLED lighting fab. The project saw many delays and entered production later than planned, and KM started producing panels at low volume at around 2020. The company recently started to ramp up production, and today we hear of one of its first customers and partners, Sentry Enterprises.

Sentry, a fintech company, launched the Radiance card illumination platform, which enables credit card (and other payment card) issuers to offer a unique experience by using an OLED lighting panel embedded in the card. The OLED panel is produced by Konica Minolta. The card works without a battery, and the OLED panel is powered by the NFC receiver upon a transaction (a technology that was demonstrated by KM back in 2020).

Researchers from the University of St. Andrews in the UK, led by Professor Ifor Samuel and Professor Eli Zysman-Colman, identified the key processes controlling the efficiency of TADF OLED emitters under high brightness. This could assist material develops on their quest to design materials that maintain high efficiency at high brightness.

The researchers explain that OLEDs have lower efficiency at higher brightness, and in many TADF materials, the efficiency roll-off is severe, so that the high efficiencies achieved at very low brightness are not maintained at higher brightnesses needed for displays or lighting applications. For the first time, the researcher identified the key processes controlling the triplet population, and propose a figure of merit for efficiency roll-off.  

Researchers from the UK's Northumbria, Cambridge, Imperial and Loughborough universities developed a new Hyperfluorescence OLED emitter system based on a new molecular design, which is highly efficient and simple to produce.

The researchers explain, that in Hyperfluorescence  systems, the elimination of the Dexter transfer to terminal emitter triplet states is the key towards OLED efficiency and stability. Current devices rely on high-gap matrices to prevent Dexter transfer, which unfortunately leads to overly complex devices from a fabrication standpoint. The researchers developed a novel molecular design in which ultranarrowband blue emitters are covalently encapsulated by insulating alkylene straps. 

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.

Researchers Durham University, led by Professor Andrew Monkman, discover new OLED emitters that offer high performance in a hyperfluorescence emission system. The main new material, a molecule called ACRSA, was found to triple the efficiency of hyperfluorescence OLED devices.

These OLED emitters aren't actually new - they were studied years ago, but were found to be poor emitters. That was true when used as OLED emitters, but when used in a hyperfluorescence system (which combines both fluorescent and TADF emitters), these were surprisingly efficient. The ACRSA emits a green emission, but deep blue light emission can be achieved by transferring ACRSA's energy to a blue terminal emitter. This approach reduces exciton energy compared to direct blue emission in devices, allowing more stable, longer-lasting blue OLEDs.

Researchers at Lawrence Berkeley National Laboratory (Berkeley Lab), led by Prof. Peidong Yang, developed a new 3D printing ink based on perovskite materials, that exhibits unity photoluminescence quantum yield (PLQY). Interestingly, as it is a 3D printable ink, it is possible to create luminescent objects from it, as seen in the image below:

The researchers brand the new ink as 'supramolecular ink', and say it is produced without any rare metals. It is a combination of several powders containing hafnium (Hf) and zirconium (Zr), and is made at room temperatures. In a process called supramolecular assembly, tiny molecular building block structures are self-assembled within the ink. These supramolecular structures enable the material to achieve stable and high-purity synthesis at low temperatures.

In 2023, we reported on research conducted at Germany's Max Planck Institute, led by Prof. Paul W.M. Blom, that looks into single-layer OLED devices. In such devices, a single TADF OLED emitter layer is sandwiched between two electrode - a much simpler design compared to commercial OLED devices that use multilayer stacks, sometimes with 10 or more layers. The researchers the the MPI say that in fact it is possible to develop highly efficient OLEDs with just the TADF emitter - and have demonstrated 100% IQE single-layer devices, with an EQE of 27.7%. 

Prof. Blom's group continues to improve its single-layer TADF OLED device, and have now reported that by employing a recently developed trap-free large band gap material as a host for the DMAC-BP OLED emitter, a nearly balanced charge transport is achieved. The device achieves a record power efficiency for DMAC-BP TADF OLEDs of 82 lm/W - surpassing  the best reported multilayer power efficiencies of 52.9–59 lm/W. This is due to the lower operating voltage. The single-layer device reaches an external quantum efficiency (EQE) of 19.6%, which is only slightly lower than the reported EQEs of 18.9–21% for multilayer devices. In addition to the high power efficiency, the operational stability is greatly improved compared to multilayer devices and the use of conventional host materials in combination with DMAC-BP as an emitter.