Displays incorporating nanomaterials are beginning to appear as prototypes and will hit the market in the next 18 months.
As well as enabling novel approaches to display designs, nanomaterials are also incorporated into display components, such as transparent electrodes, thin film transistors and coatings, sensors, transparent conductors, and infrared and visible photodetectors.
The global displays market is estimated to be worth around $100 billion in 2011. The likely widespread use of nanomaterials in future product development makes this potentially one of the most lucrative markets for nanotech. Multi-national companies Toshiba, Motorola, Hitachi and Samsung are all developing nanomaterial-based display technologies. Unidym and Samsung demonstrated in 2008 a carbon nanotube (CNT)-based active matrix electrophoretic display (EPD) e-paper, in which the transparent electrode is a CNT thin film. CNT-based transparent electrodes have been put forward as a candidate to replace indium tin oxide (ITO) currently used in touchscreens and LCD displays. Taiwan company XinNano Materials (http://xinnanomaterials.com) is applying CNT ink to substrates to produce transparent conducting film and anti-static film used for touch panels and flexible displays.
New wonder material graphene (profiled on page 12) is looking good for incorporation into next generation electronics and is overtaking nanotubes as the most viable candidate in this sector. Graphene is being used in transparent conductive coatings for touch screens and displays, and in 2010 Samsung followed up its nanotube flexible display prototype with one incorporating graphene. The company are conducting an ongoing research collaboration with graphene pioneers at the University of Manchester and Sungkyunkwan University to develop enhanced display technologies. Graphene is currently manufactured in two formats, powder and film. Most high-value applications for graphene, such as solar cells, electronics, transparent electrodes, and ultracapacitors utilize films rather than powder.
Another nanomaterials-based approach to the construction of displays is to use quantum dots (QD) as replacements for phosphor pixels. The colour emitted by a quantum dot can be controlled by changing its size (e.g. 6nm quantum dots are red). These quantum dots are arranged in alternating colour blocks which are excited by electrons. LEDs and displays utilizing quantum dots can be made ultra-thin, on flexible substrates and thus produced at a much lower cost.
QD emissions are also usually much narrower and more symmetric (clearer colour) than typical emissions from dyes or fluorophors, so displays and LEDs can produce much clearer colours.
Lastly, nanosilver has also emerged as a possible key component in display technology. Silver nanoparticles sinter at low temperatures and can be used for printable electronics. US-based companies Cambrios (www.cambrios.com) and Cima NanoTech (www.cimananotech) have developed conductive coatings by suspending silver nanowires in a solution. The ability to deposit the films using low-temperature processing such as roll-to-roll coating and printing makes the technology cost-effective, as opposed to high-temperature sputtering for Indium Tin Oxide (ITO). Blue Nano (www.bluenanoinc) is another start-up developing silver nanowires for displays.
Further information on nanotech-enabled next-generation displays can be found in the market report “Nanotechnology and Nanomaterials in the Electronics Sector”, published by Future Markets, Inc. (www.futuremarketsinc.com).
The Main Players…
Nokia is heavily involved in R&D on nanomaterials for next generation electronics devices and has developed the “Morph” concept highlighting how a potential future product might look. They are also part of the EU-Graphene Flagship programme.
Originally enamoured with nanotubes, Samsung has now jumped on the graphene bandwagon and has produced a prototype 25-inch flexible touchscreen made of graphene.
Hitachi has collaborations with a number of nanomaterials producers and applications developers looking at quantum dots, silver nanowires, nanotubes and graphene for displays.
The company is developing nanomaterials to replace ITO for next generation displays. Their first product is a transparent, conductive film.