OLED display technology moving to compete in TV market

SANTA CLARA, USA: According to the recently-released NPD DisplaySearch OLED Technology Report, organic light emitting diodes (OLED) technology advanced rapidly in 2011, a trend that NPD DisplaySearch forecasts will continue through this decade. OLED technology has progressed in areas including organic materials, color patterning, electronic driving methods, and encapsulation.

However, the ability to scale OLED display manufacturing to fabs larger than the current Gen 5.5 has yet to be demonstrated, and the cost of larger panels is not yet clear.

OLED emerged in the 1980s from laboratories at Eastman Kodak in the US and Cambridge University in the UK, and was first commercialized in the late 1990s. Enthusiasm has increased recently as Samsung Mobile Displays has started manufacturing active matrix OLED (AMOLED) displays in a Gen 5.5 fab and announced plans to build a Gen 8 fab (as did LG Display), and several other suppliers entered or re-entered OLED display manufacturing, including AUO, CMI, IRICO, Tianma, and BOE.

The NPD DisplaySearch OLED Technology Report details how OLEDs offer a solid-state solution for displays, lighting, and organic electronics. 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 devices that can be both flexible and transparent.

OLED display revenues are estimated to exceed $4 billion in 2011 (approximately 4 percent of flat panel display revenues), and are forecast to reach more than $20 billion (approximately 16 percent of the total display industry by 2018. In addition, OLED lighting gained momentum in 2011, and is forecast to reach revenues of approximately $6 billion by 2018.

“OLED displays operate through direct emission, as opposed to transmissive LCD or reflective displays, which enables area lighting,” said Jennifer Colegrove, VP of Emerging Display Technologies for NPD DisplaySearch. “The technology has made good progress and is ready to enter large-size applications, but low cost manufacturing for large sizes is still a challenge.”

OLED is now a mass-market technology in small/medium displays, particularly in smart phone applications. Investments in Gen 8 (2200 × 2500 mm) fabs indicate that AMOLED will compete in larger size applications, such as in TV and mobile PCs, within two years. Samsung released a 7.7” AMOLED tablet PC in December 2011, and more tablet and other mobile PCs are expected in 2012. LG is expected to enter the market in 2012 with a 55” AMOLED TV. With technology improvements, NPD DisplaySearch forecasts AMOLED will enter other applications as well.

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 1: Comparison of LTPS, a-Si, and Oxide TFT for AMOLEDSource: NPD DisplaySearch OLED Technology Report, USA.

The NPD DisplaySearch OLED Technology Report includes some other key findings:

* Organic materials of all types have efficacies ranging from less than 10 to nearly 100 cd/A. Large increases in efficiency 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.