OLED trends: Materials, color patterning advances and the display race

January 6, 2012 — Organic light emitting diode (OLED) manufacturing advanced rapidly in 2011, making gains in organic materials, color patterning, electronic driving methods, and encapsulation, shows the NPD DisplaySearch OLED Technology Report. This trend will continue through the decade.

OLEDs are a solid-state technology for displays, lighting, and organic electronics.

Organic materials have efficacies from <10 to nearly 100cd/A. Large efficiency increases have been obtained with phosphorescent materials, especially in red and green.

Nearly all AMOLED displays are made using thermal evaporation through a fine metal mask (FMM) for color patterning. However, this method has low material utilization and is limited to small substrate sizes. Manufacturing processes with higher material utilization and better uniformity, such as linear and area sources, are likely to be adopted. Other color patterning methods, such as white with color filter and solution-processed materials, are also evolving and ready to be adopted for mass production in larger generation fabs.

OLED lighting gained momentum in 2011, and is forecast to reach revenues of approximately $6 billion by 2018.

OLED display revenues are estimated above $4 billion in 2011, approximately 4% of flat panel display revenues. This will top $20 billion, or approximately 16% of the total display industry, by 2018. OLED displays have a mass market in small/medium applications, such as smartphones.

OLED displays can provide high contrast ratio, fast response time, wide color gamut, and wide viewing angle, while operating in a broad temperature range at low power consumption. In addition, OLED technology enables thin, flexible displays and transparent devices.

Scaling OLED display manufacturing beyond the Gen 5.5 fabs is yet to be accomplished, and the cost factor with larger OLED displays is yet to be determined, the report shows. Samsung Mobile Displays and LG Display have plans for Gen 8 (2200 × 2500mm) OLED fabs. Investments in Gen 8 fabs indicate that AMOLED will compete in larger size applications, such as in TV and mobile PCs, within two years, Strategy Analytics predicts.

Other suppliers — AUD, CMI, IRICO, Tianma, BOE — are entering or re-entering the OLED fab sector. OLED display technology, which operates through direct emission, "has made good progress and is ready to enter large-size applications, but low-cost manufacturing for large sizes is still a challenge," said Jennifer Colegrove, PhD, VP of emerging display technologies for NPD DisplaySearch.

While nearly all AMOLEDs on the market are currently based on LTPS, several companies are developing AMOLEDs using oxide or a-Si TFT backplanes, and are likely to start production in 2012.

Table. LTPS, a-Si, and Oxide TFT for AMOLED. Source: NPD DisplaySearch OLED Technology Report.
Characteristic LTPS
a-Si Oxide TFT
Electron mobility Excellent: 10-500 cm²/VS Poor: 0.5 cm²/VS Good: 1-40 cm²/VS
Uniformity Poor Excellent Good with amorphous type;
poor with crystalline type
Stability Excellent Poor Poor
Scalable Limited to <40” Excellent, >100” Potential to 100”
Process temp High: >400°C Typical ~300°C,
some low temp process can be 150°C
Typical ~200°C,
but some anneal at 350°C
Cost High Low Medium
Availability Yes: MP Demo for AMOLED; Announced by
RiTdisplay and IGNIS; MP late 2011
Demo for AMOLED;
MP estimated in 2012
Challenges Uniformity, cost, scalability Poor mobility; poor stability Threshold voltage unstable; manufacturing process not mature

The 5NPD DisplaySearch OLED Technology Report provides a detailed discussion on the rapid growth and adoption of OLED technology: historical data on OLED technology, organic material development, electronic driving types (passive matrix, LTPS TFT, a-Si TFT, Oxide TFT, organic TFT, etc.), color patterning methods, capacity analysis and a market forecast through 2018. It includes analysis on solutions for the bottleneck in mass production for OLED color patterning. This report also discusses the current status of the OLED industry, developers in each region, and new opportunities. NPD DisplaySearch is a market research and consulting firm specializing in the display supply chain, as well as the emerging photovoltaic/solar cell industries. For more information on NPD DisplaySearch analysts, reports and industry events, visit http://www.displaysearch.com/.

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