Technical / Research - Page 51

Raymond Soneira, our friend and display guru from DisplayMate have posted a very interesting and detailed comparison of the OLED displays in the Galaxy S, SII and SIII phones. He says that while all three OLED panels performed very well, there has been a rapid and significant improvement in OLED performance (especially power efficiency) in just 2 years.

Raymond says that high-end LCDs are brighter and more power efficient than OLEDs for text and web applications. OLEDs are better for photos and videos. He also says that while the performance is excellent, it's been compromised by Samsung's implementation choices - especially the low brightness due to power constraints (although low reflectence on those devices mean that high brightness is not critical in most situations).

The Korean government is funding a new program ("Future Flagship Program") that will develop transparent and flexible OLED technologies with an aim to produce ultra high-definition 60" flexible OLED displays by 2017. The project will be led by LG Display, and will also include equipment-maker Avaco.

Flexible OLED TV concept (Sony)

The Korean Ministry of Knowledge Economy is spearheading the program, and they say that this technology may have a large impact on the Korean economy, creating 840,000 jobs and $56 billion in yearly exports. It will also help to widen the technological gap between Korea and China in the display sector. The Korean government chose several key technologies that will help to further develop the industry, and OLED is one of them.

COMEDD published an interesting article detailing their current R2R research line. The vacuum deposition and fabrication of small-molecule OLEDs is made in the RC 300-MB roll-to-roll vacuum coater (supplied by Von Ardenne Anlagentechnik). This machine is capable of processing metal and plastic substrates (300 mm width). The article also details the encapsulation, inspection and defect-detection processes.

COMEDD (Center for Organic Materials and Electronic Devices) is now an independent Fraunhofer institute (it was established as a department in at the Fraunhofer IPMS originally). COMEDD's aim is to carry out customer R&D and pilot fabrication of vacuum-processed organic materials applications.

Air Liquide says it has been selected to supply ultra-pure carrier and electronic specialty gases to three new fabs manufacturing advanced display technologies, such as OLEDs, LTPS, MEMS, and OLED backlighting (we assume they mean OLED lighting). The fabs are located in Singapore, Japan and Taiwan. All those fabs will produce small/medium displays for smart phones and tablets.

We know of new OLED fabs in all those locations: in Japan several companies (such as Lumiotec, Mitsubishi and Panasonic) are producing OLED lighting panels. Both CMI and AUO in Taiwan are gearing up toward AMOLED production, and in Singapore AFPD (a 4.5-Gen LTPS fab owned by AUO) is also upgrading the LTPS LCD fab to OLED production. Any of these fabs may have selected Air Liquide's product.

Novaled announced it has entered into a licensing and purchase agreement with Samsung Mobile Display (SMD). SMD committed to buy Novaled's dopant materials for AMOLED transport layers for several years. Novaled will also provide its PIN OLED technology to SMD.

Samsung has cooperated with Novaled since 2005, although this hasn't been officially declared until recently, when Novaled published some documents for their upcoming IPO. In September 2011, Samsung investment in Novaled (we do not know the amount). Novaled is offering OLED technology licensing, consulting services and OLED materials, and they also list LG Display as a customer. In 2011, the company reported €17.4 in revenues and a profit of €1.2 million.

During SID, the Fraunhofer IPMS unveiled their bi-directional OLED microdisplay evaluation kit - which comes with a demo unit and software API so you can design your own application. The HMD is see-through and features eye-tracking, all of this from a single OLED device. The kit costs around €11,000 euro (almost $14,000).

The application they were demonstrating at SID showed a map of the world. If you looked in some directions, the map moved. I couldn't actually get this to work myself... but apparently this system works great for others, as they won the Best of Show at SID.

Just before SID, the Flexible Display Center (FDC) at Arizona State University (ASU) announced that they managed to fabricate the world's largest (7.4") flexible (bendable) OLED using Mixed-Oxide TFTs. Those MO-TFTs deliver high performance (fast switching speeds and reduced power consumption), are quite cost-effective and can be produced on existing a-Si production lines. The FDC demonstrated this panel at SID.

This OLED panel was developed with funding from the US Army features 480x360 (81 ppi) resolution, has an Oxide-TFT (IGZO) backplane and is built on a PEN (polyethylene naphthalate) substrate. It was developed in collaboration with Universal Display, DuPont (Teijin film), Sunic and Henkel.

Corning's major announcement at SID was the new Willow glass product. This is an ultra-slim (50 um and 100 um) flexible glass that can support backplanes and color filters in both LCD and OLED panels. Willow glass can withstand temperatures up to 500 degrees Celsius, and can be used in roll-to-roll production processes.

Corning says that in the near future Willow glass can be used to produce rigid OLEDs panels in processes that need flexible glass (such as roll-to-roll), and in the long term it may also lead to actual flexible panels based on glass. Glass have several advantages over plastics, mainly that it's a better barrier and it can result in better displays in terms of resolution, backplane speeds, etc. However the major disadvantage is that it can be shattered, unlike plastic-based displays.

Chimei Innolux had a nice booth at SID 2012, and I was given a nice tour of the booth by their PR people (who allowed me to take photos and videos even though they had a sign saying it ain't allowed). CMI's marketing guys were also kind enough to answer a few questions I had on their OLED program.

A few days before SID CMI announced that it will begin to produce 3.4" and 4.3" panels by Q4 2012. At SID I learned that the first OLED fab to go online is actually an old TPO/Toppoly 3.5-Gen fab. The panels will use LTPS backplane and will both feature 960x540 resolution (so it's 326 ppi on the 3.4" panel and 257 ppi on the 3.4" panel). CMI says that their technology is "ready" for 4.5" 720p (326ppi) panels as well.

Sony released 0.5" 1024x768 (2,560 ppi, 9.9um pixel pitch) and 0.7" 1280x720 (2,098 ppi, 12um pixel pitch) OLED microdisplays back in August 2011, and now they gave some interesting details about the technology used to fabricate those panels. The 0.5" OLEDs are used in several 'A' class digital cameras, and the 0.7" microdisplays are used in the HMZ-T1 HMD device.

We already know that the microdisplays use white OLEDs with RGB color filters (all OLED microdisplays on the market use this architecture, although eMagin are working on direct-emission ones). Sony are using stacked RGB fluorescent materials. They say they did not choose red and green PHOLEDs because of lifetime, reliability and cost considerations.