Carbon Nanotubes

Carbon nanotubes and graphene exhibit extraordinary electrical properties for organic materials, and have a huge potential in electrical and electronic applications such as sensors, microelectronic and semi-conductor devices, field emission displays (FEDs), nanoelectrodes and energy conversion devices (e.g., fuel cells and batteries).

Depending ontheirchemical structure carbon nanotubes (CNTs) can be used asanalternative to organic and inorganic semiconductors, as wellasconductors, but the cost is currently the greatestrestraint.However, that has the ability to rapidly fall asapplications growand manufacturing costs improve. Interest is highas CNTs havedemonstrated carrier mobilities which are magnitudeshigher thansilicon, meaning that fast switching transistors can befabricated.This is in contrast to polymer organic materials thatmanycompanies are developing for transistors, where the mobilityiscurrently very low, severely restrictingpossibleuses. Seventy-eight organizations working on the topicareprofiled in a new IDTechEx report. For moredetails,visit www.IDTechEx.com/nano. 

In electronicsoneof the first applications for CNTs will be transparentconductors.Here, applications are for displays, replacing ITO,touch screens,photovoltaics and display bus bars, connecting TFTsto the frontplane, such as OLEDs.

IDTechEx's sixthannualPrinted Electronics & Photovoltaics USA Conference,December2-3, 2009 in San Jose, California, covers alltheapplications, technologies and opportunities in the fieldofprinted electronics and photovoltaics. This event, theworld'slargest on the topic and growing rapidly every year, willhave over100 world-class speakers--some presenting exclusively forthe firsttime here--covering components, materials andapplications. Enduser speakers include representatives from Procter& Gamble andKimberly Clark, among others.

For the firsttime,IDTechEx will have a session dedicated to the rapidly growingtopicsof CNTs and Graphene for electronics applications, withkeycompanies and research institutes presentingtheirwork:

Founded in2004,Canatu is a spin-off from the Helsinki University ofTechnology(TKK) producing films based on carbon nanotubes and theirNanoBud™nanomaterial CNT films. Dr David Brown, CEO, will speakaboutgraphene and carbon nanotubes, especially key innovationsandtheir commercialization as transparent electrodes,semiconductors,resistors, capacitors and saturable absorbers in thedisplay,solar, touchscreen and laser markets. These key innovationsareCarbon NanoBuds™, hybrids between traditional CNTs andfullerenes,their CNT and NanoBud™ synthesis processes and thecomponentproduction method called Direct Dry Printing™, which isable toproduce superior quality homogeneous and patterned films,eitherfree-standing or on virtually any substrate atroomtemperature.

Canatu isfocusingon applications of conductive and semiconductive thinfilms, whichrange from transparent electrodes in solar cells anddisplays,saturable absorbers in pulsed lasers to semiconductingfilms infield effects transistors. Their patterned transparentconductivefilms are suitable for replacing ITO in LCDs, OLEDdisplays, thinfilm solar cells, etc. Canatu is working withcompanies onintegrating their films into applications in the areasofe-readers, touch screens, thin film displays andsolarcells.

CanatutoldIDTechEx, "We will be selling homogeneous and pre patternedfilmsin various conductivities, transparencies, patterningandfractional coverage. We will begin by supplying selectedstrategicpartners with specialty films made to theirspecifications." Browntells IDTechEx that they see 300% growth inshipments over the nextfive years.
Locatedbetween San Francisco and San Jose,California in the heart ofSilicon Valley, Stanford Universityis recognized as one of theworld's leading research and teachinginstitutions. One of thewidely spread research areas at Stanfordare CNT-based Macro andNanoelectronics with projects on thefundamental understanding ofmolecule-CNT interaction, thedevelopment ofmetallic/semiconducting CNT separation techniques,the fabricationand optimization of large-area film transistors frompurified CNTs,as well as self-assembly and patterning ofCNTs.

One groupofresearchers as Stanford University is working on the utilizationofprintable carbon nanotubes in high performance energystoragedevices. Professor Yi Cui, Assistant Professor of materialsscienceand engineering at Stanford University will talk abouttheirresearch for new extremely cheap completely printedsupercapacitorswith ultrahigh specific energy and power, completelyprintednanotube current collectors for batteries, andstretchable,flexible and wearable nanotube energystoragedevices.

Sohrab Kianian,VPof Business Development at Nantero Inc., a nanotechnologycompany,will give an insight to their development of carbonnanotube memoryand electronics, especially nanotube-based datastorage devices.Their high-density nanotube-based non-volatilerandom access memory(NRAM) device is fabricated incorporatingsuspended, single ormulti-walled CNTs. The company is confidentthat the logic gatescan be integrated with Complementary MetalOxide Semiconductor(CMOS) technology.

As result ofacollaboration with SVTC Technology that was established in2008Nantero's proprietary "CMOS-friendly" CNT process will beinstalledat SVTC's two development fabs, in San Jose, Californiaand Austin,Texas. Apart from their main focus--development of NRAM™universalmemory--Nantero is also working with licensees onothernext-generation semiconductor devices incorporating CNTtechnology,e.g. logic and sensors.

The UniversityofCalifornia Los Angeles (UCLA) is a leading academic instituteinthe state active in various fields related to the topic, as wellasprinted electronics and photovoltaics. Yang Yang, a professorofmaterials science and engineering at UCLA, will presenttheirfindings with hybrid graphene-carbon nanotube material(G-CNT). Theresearchers developed a single-step to fabricate G-CNTsin an easy,inexpensive and scalable method. The transparentconductors showgreat potential to be a high-performance alternativeto ITO e.g. inflexible solar cells and other flexible consumerelectronics. Incomparison to ITO G-CNTs retain efficiency whenflexed and arecompatible with plastics.

Whileseveralorganizations have demonstrated CNTs and Graphene fortransistors,such as NEC Corporation, HRL Laboratories, IBM,Optomec, Fujitsuand AIST, it will take time before these arecommercialized.Conservatively, IDTechEx anticipate this may beavailable in volumefrom 2015 onward or, more optimistically, itcould be two yearsearlier.
Graphene andmultiwall CNTs (MWCNTs) are alreadyin fairly high production--tensof tonnes per year. Estimates of theamount of MWCNTs produced in2008 are about 100 tons in total fromcompanies such as Bayer andShowa Denko. In 2009, the amountdelivered could double. However,most of these uses are for nonelectronic/electrical products, orsimple applications such aselectromagneticshielding.

Challengesarematerial purity, device fabrication and the need for otherdevicematerials such as suitable dielectrics. However, theopportunity islarge, given the high performance, flexibility,transparency andprintability.

IDTechExprovidesinsight in the field of CNT and graphene for printedelectronicsand photovoltaics in the newly published reportCarbonNanotubes and Graphene for Electronics Applications:Technologies,Players &Opportunities. This concise andunique reportgives an in-depth review of the applications,technologies,emerging solutions and players. Formoreinformation