Long-term market outlook may shine for OLED displays
08/01/2001
Kimberly Allen, Stanford Resources, San Jose, California
Organic light-emitting diode (OLED) technology used in color displays that feature excellent image quality, especially in contrast and brightness, is generating big interest in the display sector and across the world of electronics. Because of its promise, more than 80 companies are developing businesses for OLED displays, components, materials, and manufacturing equipment.
OLED applications — principally, cellular phones — are expected to multiply beginning around 2002, according to market research firm Stanford Resources. The long-term market outlook is promising, provided the new technology can establish a manufacturing infrastructure that will allow it to compete against liquid crystal display (LCD) and other device technologies.
Promising growth projected
OLED products entered the market with simple displays in the form of small-sized, passive matrix, monochrome or multicolor panels with very few pixels. Soon, OLED products will have more pixels and additive color subpixels, but will remain passive and small in size for the time being. Plenty of applications exist for which such panels are suitable, due to the current proliferation of handheld electronic devices and other products featuring small, flat-panel displays.
 Figure 1. Active and passive OLED display units. |
All current OLED products are passive matrix with the exception of OLED microdisplays; however, numerous companies have demonstrated laboratory samples of direct-view, active matrix OLED displays. Kodak-Sanyo showed a 5.5-in., full-color, active matrix OLED display in 2000, and Sony and Samsung SDI followed suit this year with 13-in. and 8.4-in. active matrix displays. CDT and Seiko Epson demonstrated the first active matrix OLED made with polymer material. The device has 150 x 200 pixels on a 2.1-in. (diagonal) panel, with 16 color gradation levels. These are expected to reach the market in 2 to 3 years, but true mass production capability will not be available until a few years later.
Stanford Resources estimates the worldwide market for OLED displays at $84 million for 2001, growing to $1.6 billion in 2007, with a compound annual growth rate of 63%. A total of 925,000 units were sold in 2000; 3.2 million will likely be sold in 2001; and unit shipments will grow more than 60-fold to 195 million in 2007.
 Figure 2. Active and passive OLED display value. |
Stanford Resources also projects that in 2004, 535,000 active matrix OLED displays will be sold, for a total value of $45 million, which represents 1% of the worldwide OLED display market in units, and 8% in value. In 2007, active matrix OLED products will account for 6% of the units and 32% of the value. The largest portion of the active matrix value in 2007 (47%) will come from cellular telephone displays. Other key active matrix OLED applications include camcorders, digital still cameras, and automobile displays.
The highest-value passive matrix application for OLEDs in 2007 will be cellular telephone displays, which will garner $549 million, comprising 51% of the passive matrix OLED display market and 34% of the total OLED display market. The addition of active matrix OLED products to the market beginning in 2003-2004 will add significantly to market value, as shown in Figs.1 and 2.
OLED technology
Light emission from small-molecule organic systems was discovered by Ching-Wai Tang and Steven van Slyke of Eastman Kodak in 1987. Kodak patented this materials know-how and has since licensed it to 11 other companies that have continued its development.
Tohoku Pioneer was the first to introduce a commercial OLED in the form of a 256 x 64-pixel car radio display introduced in 1997. The first wireless phone handset featuring a color OLED carries the Motorola name, but Pioneer actually supplies these OLEDs. Pioneer operates two manufacturing lines that use 300mm x 420mm glass sheets. About 10,000 sheets/month, or almost 1 million panels/month, can be processed, although yields are still quite low. Another Kodak licensee, RiTDisplay of Taiwan, has retooled its CD-R equipment for small-molecule OLED (SMOLED) manufacturing, and has developed an OLED display for a handheld game, which will be sold in 3Q01.
Kodak continues to be a major proponent of SMOLED technology. Sanyo Electric, LG Electronics, Samsung NEC Mobile Display, and Sony are other companies that are highly involved in commercializing SMOLEDs. TDK has built a small line and will soon enter the car stereo display market with its Bio EL, also made with Kodak's small-molecule technology. The product will be used in Alpine's line of car stereos for cars sold in Japan.
In 1990, Jeremy Burroughs, working in the research group of Richard Friend at Cambridge University, found that conjugated polymers had similar light-emitting qualities. Friend founded Cambridge Display Technology (CDT) on the basis of the resulting patents. As with small-molecule technology, however, many other polymer materials have become available recently.
In addition to CDT, companies pursuing polymer OLEDs (PLEDs) include Philips, Toshiba, and Seiko Epson.
Other players are focused on providing materials for OLED devices, including DuPont, Nippon Steel Chemical, and Idemitsu Kosan in the small-molecule arena, and Dow Chemical in polymers. Covion, a German joint venture of Avecia and Aventis, is developing both materials. Although both PLEDs and SMOLEDs are being developed for commercial products, only small-molecule products have actually made it to the market.
OLED advantages and challenges
OLED displays offer some major advantages over other types of flat panels, and in particular, the LCD, its prime competitor. Because it is an emissive technology, it offers superior viewing angles and contrast ratios as compared with the LCD. Furthermore, its response time is faster, which may play a role when OLEDs are used in active matrix applications. OLEDs can be made extremely thin and lightweight, which is handy for cellular phones and other handheld devices. Also, they may eventually be produced on plastic or other flexible materials. One of the biggest advantages is the OLED display's potential for lower power consumption compared to the backlit color LCD, at least for small panel sizes.
Another advantage is that OLED technology does not need a backlight, which consumes a large fraction of an LCD module's power. OLED display drivers, too, are not significantly more power-hungry than LCD drivers, although power consumption does increase with display area and brightness. For small panels, such as those used in handheld electronics, OLEDs have already been demonstrated to consume less power than comparable LCDs. Kodak and Sanyo, for example, have reported that their 2.4-in. active matrix OLED module consumes 440mW, compared to 605mW for a 2.4-in. polysilicon LCD module.
This savings will improve the length of time that small electronics can be used between battery changes (or they can operate for the same time with a smaller battery and package). This is an advantage for cellular phones, PDAs, and other mobile devices.
Despite these demonstrations, much research and development work needs to be done. For example, today's OLED materials fall short in terms of performance over a product lifespan. Substantial R&D work is needed to prolong OLED lifetime performance.
As with any electronic devices, the key to bringing OLED products to market is manufacturing in large volumes. Big volumes will result in a substantial reduction in the prices of OLED displays for wireless phones and many other applications.
But even beyond the savings that come with large volumes, OLEDs offer potential for manufacturing cost savings. The LCD manufacturing process has proved to be expensive and difficult to scale; upgrading to a larger substrate size costs more than $500 million. OLED manufacturing promises to be simpler, in that it requires fewer layers and is more readily scalable.
A basic OLED device has just four functional regions, which may not all be separate materials: two charge-transporting layers, a charge injection layer, and the zone from which the light actually shines. These layers are sandwiched between two electrodes. This is simpler than an LCD, which requires alignment layers and other structures to control the light modulation. SMOLED materials are deposited in a vacuum chamber, while polymer materials are applied by a large-area process such as spinning or inkjet printing.
A significant hurdle remains, however. Appropriate manufacturing processes, standardized across the global industry, must be put into place. No standardized processing and test equipment exists for OLEDs. Lines are yet to be built and manufacturing techniques optimized. It is important to emphasize that building OLED mass production capability is the critical task for the industry in the next few years.
The OLED industry is benefiting from the timely convergence of OLED technical development with the growing market demand for small, relatively simple flat-panel displays, particularly low-power ones. This situation is providing the crucial early building blocks to help OLED technology gain a footing in the market. If the manufacturing infrastructure for OLED panels can evolve in concert with the market, OLED manufacturers can ride this wave for many years, as OLED devices evolve to full-color, active matrix, and larger-sized panels, just as the LCD did.
Kimberly Allen is director of technology and strategic research at Stanford Resources, 20 Great Oaks Blvd., Suite 200, San Jose, CA 95119; ph 408/360-8400, fax 408/360-8410, e-mail [email protected], www.stanfordresources.com.
Stanford Resources, a wholly-owned subsidiary of iSuppli Corp., publishes numerous annual and quarterly reports on the electronic display industry, including Organic Light-Emitting Diode Displays, Mobile Display Systems, Monitor Market Trends, Flat Panel Monitor Market Trends, Liquid Crystal Displays, Plasma Display Panels, Projection Displays, and Microdisplays. The company also provides a wide range of management consulting services.