Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Thermochemical nanopatterning of organic semiconductors

Figure – A schematic of the Wollaston wire probe and the lithographic process (bottom). a Regular patterns drawn over large areas using scanning thermochemical lithography. The top image is an atomic force micrograph, whilst the bottom image is from a confocal microscope. b Atomic force microscope image of a high resolution lithographic line (top) and its cross-section (bottom).
Figure – A schematic of the Wollaston wire probe and the lithographic process (bottom). a Regular patterns drawn over large areas using scanning thermochemical lithography. The top image is an atomic force micrograph, whilst the bottom image is from a confocal microscope. b Atomic force microscope image of a high resolution lithographic line (top) and its cross-section (bottom).

Abstract:
Researchers from the London Centre for Nanotechnology (LCN) and University College London (UCL) have fabricated sub-30 nm luminescent features of an organic semiconductor via spatially selective conversion and patterning of its precursor by using a heatable, micron-size scanning probe (see figure below). The results will soon be reported in the journal Nature Nanotechnology.

Thermochemical nanopatterning of organic semiconductors

London | Posted on September 8th, 2009

The future development of electronics and photonics relies on a range of sophisticated lithographyic techniques for the patterning of semiconducting, dielectric, and metallic materials. Researchers at the London Centre of Nanotechnology (LCN), the Department of Physics and Astronomy, and the Eastman Dental Institute at UCL, have now developed a thermochemical patterning technique for materials known as organic semiconductors.

These materials can be used in light-emitting diodes (LEDs), solar cells, lasers and transistors, and their potential is in low processing costs and the ability to build devices on flexible substrates. However, applications of these materials in nanoelectronics and nanophotonics are limited by the range of patterning techniques available. Many of the approaches to nanolithography that are used to pattern inorganic materials, such as e-beams or Focused Ion Beams (FIBs), are too harsh for organic semiconductors, that can be damaged by the high energy of the patterning beams, or by the chemicals needed for the processing.

So, instead of using standard optical or other "conventional" high-resolution lithographies, the UCL researchers used a small heat source for the patterning. This heat source, known as a modified Wollaston wire, can be mounted on an atomic force microscope and scanned across surfaces to chemically convert all areas it comes into contact with. This technique has allowed the UCL researchers to achieve patterned resolutions below 28 nm and write speeds of 100 µm/s in the widely used organic semiconductor, PPV. The result is particularly surprising given the large diameter of the heat source (5 µm) compared to the resolutions achieved, and since it is likely that resolution could be further improved with the use of nanoscale heat sources, as already reported by other groups.

There has already been some commercial interest in using atomic force microscopes to pattern surfaces, as for example by IBM in their ‘millipede' project, that was aimed at data-storage applications, but such a thermochemical approach opens up new possibilities. In particular, this work shows that thermochemical lithography offers a versatile, simple and reliable nanopatterning technique. For example, thermo-crosslinkable additives could easily be added to a variety of other solution-processible semiconductors. The technique should also be generally applicable to other classes of materials. A large number of optical materials, including many commercial cross-linker additives and photoresists, rely in fact on chemical mechanisms that can also be thermally activated.

The group, led by Franco Cacialli, has previously used scanning near-field optical lithography (SNOL) for nanopatterning of PPV structures from the same precursor polymer, poly(p-xylene tetrahydrothiophenium chloride) (PXT). This work included the fabrication of quasi-periodic two-dimensional structures with potential for photonic applications. However, the thermochemical technique now developed (Scanning Thermal lithography, or SThL) enables one to bypass the UV insolubilisation step, and the complications and additional costs imposed by the needs for lasers, optics, and sophisticated optical fibre probes.

More details regarding the research in the Organic Semiconductors Group led by Franco Cacialli can be found at the website: www.cmmp.ucl.ac.uk/~fc/OS/

####

About London Centre for Nanotechnology (LCN)
The London Centre for Nanotechnology, LCN, is a UK based multidisciplinary enterprise operating at the forefront of science and technology. It is a joint venture between University College London and Imperial College London and is based at the Bloomsbury and South Kensington sites. It has a unique operating model that accesses and focusses the combined skills of the departments of chemistry, physics, materials, medicine, electrical and electronic engineering, mechanical engineering, chemical engineering, biochemical engineering and earth sciences across the two universities.

For more information, please click here

Contacts:
Bloomsbury (UCL) Site
London Centre for Nanotechnology
17-19 Gordon Street
London WC1H 0AH
tel: +44 (0)20 7679 0604
fax: +44 (0)20 7679 0595

Copyright © London Centre for Nanotechnology (LCN)

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Display technology/LEDs/SS Lighting/OLEDs

New technology using silver may hold key to electronics advances July 2nd, 2015

News and information

Discovery of nanotubes offers new clues about cell-to-cell communication July 2nd, 2015

Nanospiked bacteria are the brightest hard X-ray emitters July 2nd, 2015

Engineering the world’s smallest nanocrystal July 2nd, 2015

Producing spin-entangled electrons July 2nd, 2015

Chip Technology

The quantum middle man July 2nd, 2015

New technology using silver may hold key to electronics advances July 2nd, 2015

Influential Interfaces Lead to Advances in Organic Spintronics July 1st, 2015

Emergence of a 'devil's staircase' in a spin-valve system July 1st, 2015

Nanoelectronics

New technology using silver may hold key to electronics advances July 2nd, 2015

Exagan Raises €5.7 Million to Produce High-efficiency GaN-on-Silicon Power-switching Devices on 200mm Wafers: Leti-and-Soitec Spinout Focused on Becoming Leading European Source Of GaN Devices for Solar, Automotive, Telecoms and Infrastructure June 25th, 2015

Nanowires could be the LEDs of the future June 25th, 2015

Leti to Present Solutions to New Applications Using 3D Technologies at SEMICON West LetiDay Event, July 14: Leti Experts also Will Speak at TechXPOT Session on MEMS and STS Session on Lithography Cost-and-Productivity Issues Below 14nm June 22nd, 2015

Announcements

Nanospiked bacteria are the brightest hard X-ray emitters July 2nd, 2015

Engineering the world’s smallest nanocrystal July 2nd, 2015

Producing spin-entangled electrons July 2nd, 2015

NIST Group Maps Distribution of Carbon Nanotubes in Composite Materials July 2nd, 2015

Tools

NIST ‘How-To’ Website Documents Procedures for Nano-EHS Research and Testing July 1st, 2015

Ultra-stable JILA microscopy technique tracks tiny objects for hours July 1st, 2015

Bruker Introduces Second-Generation Inspire Nanochemical Imaging Solution: Featuring Unique PeakForce IR and IR EasyAlign Technology July 1st, 2015

Carnegie Mellon chemists characterize 3-D macroporous hydrogels: Methods will allow researchers to develop new 'smart' materials June 30th, 2015

Photonics/Optics/Lasers

Making new materials with micro-explosions: ANU media release: Scientists have made exotic new materials by creating laser-induced micro-explosions in silicon, the common computer chip material June 29th, 2015

Opening a new route to photonics Berkeley lab researchers find way to control light in densely packed nanowaveguides June 27th, 2015

The quantum spin Hall effect is a fundamental property of light June 25th, 2015

Laser spectroscopy: A novel microscope for nanosystems June 25th, 2015

Solar/Photovoltaic

Making new materials with micro-explosions: ANU media release: Scientists have made exotic new materials by creating laser-induced micro-explosions in silicon, the common computer chip material June 29th, 2015

Spain nanotechnology featured at NANO KOREA 2015 June 26th, 2015

Stanford researchers stretch a thin crystal to get better solar cells June 25th, 2015

Toward tiny, solar-powered sensors: New ultralow-power circuit improves efficiency of energy harvesting to more than 80 percent June 23rd, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project