OLED display technology is continuing to advance for next generation products, a glimpse of which was seen through various presentations at the OLEDs World Summit 2020 conference from Sept 30th to Oct 2nd. Technology development, improvements in materials, advancements in inkjet printing combined with capacity expansion and higher competition will help OLED display to gain higher market share in the future.
OLED Display: Competition increasing
OLED is already leading in terms of display performance and steadily increasing market share. According to Omdia’s presentation at OLEDs Summit,
“Korean OLED makers lead the OLED capacity with 67% in 2020, but China is challenging Korea with 31% capacity in 2020 and continuous expansion. Chinese OLED makers grew substantially in 2020 with improvements in the flexible OLED yield rate and customers adoption”.
By 2022 China is expected to have nine Gen 6 flexible OLED fabs. The high cost of OLED displays has been a limitation for faster market share growth both in the smartphone and TV market. Technology advancements, capacity growth and higher competition can help to reduce costs and drive future growth.
Flexible Display: Gaining shares in the smartphone market
The smartphone market has slowed down substantially in 2020 and is expected to recover with positive growth in 2021 boosted by 5G adoption. The introduction of 5G-based products needing slimmer displays to accommodate 5G enabling components will increase flexible OLED demand. Integration of new technology such as fingerprint under display, touch display, and other features to reduce border & increased screen to body ratio can open up new opportunities.
Samsung Display dominates the flexible market but LGD and BOE are increasing production. More capacity is coming from companies such as Tianma, Visionox, China Star (CSOT) and others in 2020. According to DSSC presentation at OLEDs Summit
“OLED represented 23% of phone panels (including feature phones) in 2019 with 466 million units, increasing to 41% in 2024 with 889 million, limited primarily by price”.
LTPO: Enabling power savings
LTPO technology is a combination of LTPS + Oxide TFT technology that enables variable refresh rates and low power consumption. LTPS has high carrier mobility and high driving capability whereas Oxide TFT has low leakage. Many companies are working on this technology for next generation displays. According to an Omdia presentation
“Samsung Galaxy and Apple iPhone OLED are now leading the flexible OLED technology and product roadmap. Samsung Galaxy will eventually move to 4K/500+ PPI resolution and over 6.5” screen size. iPhone OLED will be moving to Touch on Thin Film Encapsulation, Driver IC COP and LTPO. Samsung called their LTPO HOP (Hybrid oxide and polycrystalline silicon). Smartphone batteries are getting bigger and power consumption matters. Regardless of LTPO or HOP, both need more photomasks than LTPS to pattern the oxide semiconductor layer and other layers, which increases the cost by 15–20%”.
High costs will make it difficult for power saving LTPO technology to be used in lower priced 5G products.
Foldable Display: Evolving with form factors
Omdia presented that
“Foldable smartphone OLED is targeting at a certain market segment with over $2,000 price tag and 7”-8” sizes. The market is expected to grow to 50 million in 2024. Samsung Display is leading the technology roadmap and has revamped the new structure from panel to touch and cover lens. The keys to achieve the real and mature foldable OLED are –
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Cover Lens with Colorless Polyimide or Ultra Thin Glass,
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Touch Sensor on Thin Film Encapsulation,
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Color filter on Thin Film Encapsulation, Under Panel Camera and
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LTPO with lower power consumption”.
Royole, supplier of the first foldable displays also presented that as display sizes increase power consumption also increases and LTPO with its capability of variable refresh rates can be used to reduce power consumption. Omdia presented that for Rollable/Stretchable AMOLED in future, two critical paths are reliability and cost. Prototypes of rollable products have already been shown in the industry: including Sharp 32-inch 4K, LG 65-inch TV, Visionox 6.47-inch display and BOE 12.3-inch rollable.
Photo-1 Samsung Z flip 5G with Ultra-thin glass
OLED Microdisplay: Offering higher brightness
The VR/AR market is expected to grow in the next five years. Companies such as HTC and Oculus have developed more stand-alone, all-in-one devices for VR with lower prices. OLED displays have been gaining higher acceptance in the VR market due to its high refresh rates, higher resolutions, and higher contrast for either direct view or microdisplay architectures. AR adoption has been slow due to high prices and low consumer acceptance.
eMagin Corporation presented OLED microdisplays for AR/VR applications. The presentation identified four major challenges for AR/VR applications:
- Displays.
- Optics,
- Content and
- Price.
Displays need high resolution, high brightness, high contrast, low power and small form factor. Optics requires large field of view (FOV), no distortion, high efficiency, lightweight and small factors. Content needs games, movies, live events, etc. and graphic processing speed. Everything needs to come together for it to be a successful business.
Display brightness is critical for AR and VR devices because of ambient light, optics inefficiency and need to eliminate motion artifacts. eMagin has developed Direct Patterning (dPd) OLED microdisplay technology and high resolution backplane design. The company has demonstrated >7500 cd/m² full color OLED microdisplay and next goal is to achieve >10,000 cd/m² product and is targeting a brightness level of >28,000 cd/m² in future.
White OLED display: Facing strong competition
White OLED TV has secured a strong presence in the premium TV market. LG Electronics, Sony, Panasonic, Skyworth, TPV, Hisense, Konka and others have all joined in using LG Display’s panels. LGD is converting LCD TV capacity to OLED and is also making additional investments.
The company will use the MMG method, combining different sizes of finished panels on one mother glass to improve efficiency and production costs. It has faced strong competition from Samsung QLED (QDEF-based LCD) TV with aggressive price reductions. According to a DSCC presentation:
“OLED only ~1% of TV units in 2019 with 3.4 million, growing to ~4% by 2024 with 12.2 million, limited by capacity, product line and high prices. OLED represented 9% of TV panel revenue in 2019 with $2.5 billion, and DSCC forecasts it to increase to 19% in 2024 with $6.4 billion”.
DSCC presented four major issues with OLED TV:
- Cost (For a 65-inch white OLED panel cost is three times the cost of QD LCD panel)
- Holdouts (no OLED TV) by Samsung and TCL (Top 2 global TV brands)
- No immediate plan for white OLED by other panel markers
- LCD price drop (2017 to 2019) opened up price gap to OLED
According to DSCC presentation
“Samsung will convert 120,000 substrates per month of a-Si LCD capacity to 30,000 substrates per month of QD OLED capacity for the first phase of Q-1. The large capacity reduction is the result of: increase in mask steps (12 masks with QDOLED), additional space for OLED frontplane, and secondary color filter for QDCC. SDC’s G8.5 LCD capacity will eventually be converted to QD OLED for 100k/month”.
QD OLED display: Ready for production
According to the Nanosys presentation at OLEDs Summit, Blue OLED+QDCC has potential advantages (over white OLED);
- Better color
- Better viewing angle (no cavity)
- Higher luminous efficiency, so could be brighter, or have less burn-in
- Single color EL provides design flexibility and no differential aging
QD OLED needs a blue light source (high efficiency, long lifetime), design and production of heavy metal-free QDs (high blue absorption and higher conversion efficiency). Nanosys is working on design, production of heavy metal-free QDs and process scalability to enable market adoption. Also inkjet printing can enable low cost fabrication of QDCC.
OLED with QDCC vs Color Filter. Click for higher resolution
QNED display: Next in line for production
DSCC presentated that Samsung is reportedly working on QNED technology in which GaN-based blue Light Emitting Nanorod LEDs will replace OLED as the blue light source. The advantages of the QNED structure over OLED include higher efficiencies, improved brightness, longer lifetimes and elimination of burnin issues that have been associated with OLEDs.
Inkjet Printing: Hoping to empower the TV application
White OLED with color filter technology has been the only successful technology up to now for large OLED displays (use by LGD). EMD Performance Materials (Merck) presented that WOLED+CF has a complex stack with >15 layers.
Inkjet Printing (IJP) OLED offers several advantages including high material utilization, a simple OLED stack and excellent color without color filters in the panel.
There are still some challenges such as lifetime improvement in soluble materials for top emission (TE) architecture and achieving the REC 2020 color gamut. A top emission stack enables a higher aperture ratio for OLED panels. Merck focuses on ink formulations for the flat films solution-based deposition process, which is crucial for high performance pure color top emission stacks.
According to the presentation, their ink formulation know how for TE and high-resolution display is suitable for 4K IT monitors and 8KOLED TVs. The UDC presentation also focused on their mask-less, solvent-less, OVJP product and formation of an OVJP company to commercialize the technology. According to the company, in their OVJP patented approach they can use the same stack in OLED for conventional and OJP, enabling RGB side by side low cost TV production.
OLED with IJP. Click for higher resolution
OLED Materials: More efficient Blue
UDC also presented about progress made in phosphorescent OLED display. The industry is continuing to make progress towards more efficient blue emitter materials. Cynora is still focusing on being a leading supplier for TADF deep blue in the long term (in the near term it is focusing on florescent blue and in midterm focusing on TADF green). Kyulux is working on commercialization of Hyperfluorescence technology. Monochrome yellow is already being used for PMOLED. Red and green Hyperfluorescence is close to commercialization and blue performance is improving.
At the OLED world Summit, discussions about microLED display technology were included in several presentations. Lumileds, the company that is developing InGaN and AllnGap mass transfer capable micro iLED technology also presented. The company said that iLEDs are well suited for medium and high luminance application and steady progress is being made on key enablers. It also concluded that in next 10 years both technologies would win.
OLED display technology is advancing in terms of materials, equipment, performance, capacity, investments and competition that will lead to lower cost and higher adoption rates for varieties of applications market in future. (SD)
Sweta Dash, President, Dash-Insights
Sweta Dash is the founding president of Dash-Insights, a market research and consulting company specializing in the display industry. For more information, contact [email protected] or visit www.dash-insights.com
