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

News and information

Iranian Researchers Planning to Produce Edible Insulin January 28th, 2015

Nanoparticles that deliver oligonucleotide drugs into cells described in Nucleic Acid Therapeutics January 28th, 2015

'Bulletproof' battery: Kevlar membrane for safer, thinner lithium rechargeables January 28th, 2015

Spider electro-combs its sticky nano-filaments January 28th, 2015

Display technology/LEDs/SS Lighting/OLEDs

Visualizing interacting electrons in a molecule: Scientists at Aalto University and the University of Zurich have succeeded in directly imaging how electrons interact within a single molecule January 26th, 2015

Transparent artificial nacre: A brick wall at the nanoscale January 22nd, 2015

New conductive coatings for flexible touchscreens – presentation at nano tech 2015 in Japan January 22nd, 2015

Nano - "Green" metal oxides ... January 13th, 2015

Chip Technology

Researchers Make Magnetic Graphene: UC Riverside research could lead to new multi-functional electronic devices January 27th, 2015

Nanometrics to Present at the Stifel 2015 Technology, Internet and Media Conference January 27th, 2015

New pathway to valleytronics January 27th, 2015

Entanglement on a chip: Breakthrough promises secure communications and faster computers January 27th, 2015

Nanoelectronics

Electronic circuits with reconfigurable pathways closer to reality January 26th, 2015

Rice-sized laser, powered one electron at a time, bodes well for quantum computing January 15th, 2015

Rapid journey through a crystal lattice: Researchers measure how fast electrons move through single atomic layers January 14th, 2015

A new step towards using graphene in electronic applications January 14th, 2015

Announcements

Iranian Researchers Planning to Produce Edible Insulin January 28th, 2015

Nanoparticles that deliver oligonucleotide drugs into cells described in Nucleic Acid Therapeutics January 28th, 2015

'Bulletproof' battery: Kevlar membrane for safer, thinner lithium rechargeables January 28th, 2015

Spider electro-combs its sticky nano-filaments January 28th, 2015

Tools

JPK opens new expanded offices in Berlin to meet the growing demand for products worldwide January 28th, 2015

Pittcon News: Renishaw adds to the comprehensive imaging options available with its inVia confocal Raman microscope January 27th, 2015

Nanometrics to Present at the Stifel 2015 Technology, Internet and Media Conference January 27th, 2015

Visualizing interacting electrons in a molecule: Scientists at Aalto University and the University of Zurich have succeeded in directly imaging how electrons interact within a single molecule January 26th, 2015

Photonics/Optics/Lasers

The laser pulse that gets shorter all by itself: Ultrashort laser pulses have become an indispensable tool for atomic and molecular research; A new technology makes creating short infrared pulses easy and cheap January 27th, 2015

New pathway to valleytronics January 27th, 2015

Scientists 'bend' elastic waves with new metamaterials that could have commercial applications: Materials could benefit imaging and military enhancements such as elastic cloaking January 23rd, 2015

Teijin to Participate in Nano Tech 2015 January 22nd, 2015

Solar/Photovoltaic

Visualizing interacting electrons in a molecule: Scientists at Aalto University and the University of Zurich have succeeded in directly imaging how electrons interact within a single molecule January 26th, 2015

Iranian Researchers Boost Solar Cells Efficiency Using Anti-Aggregates January 26th, 2015

Engineering self-assembling amyloid fibers January 26th, 2015

New technique helps probe performance of organic solar cell materials January 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







© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE