Power consumption - Page 2

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.

LG Display announced that it has developed its 2nd generation Multi-Lens Array (MLA) technology, branded as META Technology 2.0.  The company demonstrated a 83" META 2.0 OLED TV panel, during CES 2023. The company will apply this technology to several of its 2024 OLED TVs, ranging in size from 55-inch to 88". 

META 2.0 WOLED panels achieve a peak brightness of 3,000 nits - a 42% improvement over the company's conventional panels. LGD explains that META 2.0 includes a pattern of optimized micrometer-scale lenses with an optimized lens angle, an upgraded "brightness enhancing algorithm" called META Multi Booster, and a full-range brightness detail enhancing algorithm called Detail Enhancer. All of these new technologies, combined, makes for a META 2.0 panel. In a 77-inch 4K panel, there are 42.4 billion micro lenses (!).

US-based Pixelligent is an advanced materials company that delivers next generation optical materials applications in lighting and displays. For the OLED industry, Pixelligent offers materials that significantly increase light output by increasing the refractive index of materials in the device.

Pixelligent's President and CEO, Craig Bandes, was kind enough to answe a few questions we had, to learn more about Pixelligent and its solutions for the OLED industry.

Hello Craig! Can you explain your technology and materials and how they enhance the efficiency of OLED display?

We are best known for our high refractive index (HRI) nanocrystal formulations and dispersions that deliver breakthrough performance in next-generation electronics, like extended reality, displays, optics, and sensors. We designed our PixJet®, PixNIL®, and PixClear® products to offer the best combination of brightness, clarity, operating efficiencies, and device-lifetime. 

In 2021, LG Display started to adopt deuterated OLED compounds in its WOLED panels, to improve the lifetime, efficiency and brightness. Today, all of LG's WOLED TV panels use deuterated blue OLED emitters, in which hydrogen is replaced by its more stable isotope, deuterium. The higher stability enables longer lifetime, which in turn enables higher brightness and efficiency.

It is now reported in Korea that LG Display now aims to expand the adoption of deuterated OLED compounds to its red and green and yellow emitters, and also other layers in the OLED stack. If this report is true, it means that LGD will also use the technology in its mobile (p-OLED) panels, not just its OLED TV ones. 

Visionox announced that it has produced the first mass-production sample ViP AMOLED display. The company aims to start mass producing small and medium-sized ViP AMOLED soon, and later apply the technology for large-area panels as well.

The company did not detail when it expects to start actual mass production. It did update that it has already applied for over 500 patents regarding to ViP technology, over 13 different technical fields. The company also says it is in talks with several key customers to define its production process and final display capabilities.

Merck KGaA is a pioneer in high performance OLED material development, supplying a range of materials for AMOLED makers since the industry’s inception.

To learn more about Merck’s materials and views on the OLED industry, we conducted an interview with Dr. Georg Bernatz, Merck Electronics’ Global Head of OLED Technical Marketing. Georg Bernatz has received a PhD in Physics from the Philipps-Universität in Marburg, Germany in 2000. In 2004, Georg joined Merck, where, over the years, he worked in various functions and on various topics in the field of Liquid Crystals for displays. In 2018, Georg changed to OLED, leading OLED Physics Product Research, and in 2020 he became responsible for all Physics & Application Labs in Darmstadt for Display materials. Since October 2023, Georg is heading Merck’s Global Technical Marketing for OLED materials.

Hello Dr. Bernatz. Can you bring us up to date quickly on Merck's current OLED material products? What do you offer to OLED display makers?

Merck KGaA, Darmstadt, Germany is very active in the design, development and production of a broad variety of high performing OLED materials, with a strong focus on hole and electron transport materials (HTM, ETM), host materials for phosphorescent emitters as well as activities in the field of high efficiency blue.

Universal Display is progressing with its blue PHOLED material, and earlier this month the company said it is on track to introduce the new material commercially in 2024. During a company seminar, UBI's Daejeong Yoon updated that according to their latest information, Samsung Display has decided to adopt a blue phosphorescence material in the second half of 2025 - a year later than expected.

Samsung is calling the new material stack B1, and it says that the new stack will increase the efficiency of its OLED device by more than 65% (which seems to be rather too much, maybe it means 65% of the power consumption of the current stack). UBI says that the blue OLED still suffers from low lifetime - the lifetime of the blue PHOLED stack is only 55% of the lifetime of its current fluorescence-blue stack, but regardless of that the company will introduce it commercially due to the power consumption efficiency.

Dr. Kou Yoshida and Dr. Junyi Gong, from the University of St Andrews, working with Prof. Ifor Samuel and Prof. Graham Turnbull, have developed an integrated organic laser device, based on an electrically-pumped laser.

In this work, the researchers developed and electrically driven organic electronic laser, with a narrow emission spectrum and the formation of a laser beam above the threshold. The researchers have shown that indirect electrical pumping by an OLED is a very effective way of realizing an electrically driven organic semiconductor laser.

Researchers from the University of Manchester, led by Prof. Alexander Romanov, developed a promising new Carbene-Gold-Arylacetylide (CMAc) OLED near UV emitter type. The researchers also detail a strategy to develop longer device lifetimes for such emitters.

The new emitter exhibits an efficiency of 1% EQE, and a lifetime of 20 minutes at a practical brightness of 10 nits (LT50). This is low compared to commercial OLEDs - but it is actually quite outstanding for such an emitter, and the researchers say that this is among the longest lifetimes for a near UV-OLED at a practical brightness ever reported. In addition, organic fluorescent and TADF emitters rarely exceed 1% EQE at practical brightness.

Researchers from Korea's KAIST institute, in collaboration with Gyeongsang National University developed a new TADF OLED deep-blue emitter molecule that achieves an EQE of 33%. Combined with a fluorescent emitter to create a hyperfluorescence system, the researchers achieved an EQE of 35.4%, with mitigated efficiency roll-off. The researchers say that this is the world's highest-efficiency narrow-band deep-blue TADF OLED emitter.

To develop the new emitter the researchers introduced sterically hindered peripheral phenyl groups to boron-based TADF emitter. The resulting material, o-Tol-ν-DABNA-Me, offers a pure narrowband emission that is far less sensitive to concentration compared to standard TADF emitters.