Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

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

A big nano boost for solar cells: Kyoto University and Osaka Gas effort doubles current efficiencies January 21st, 2017

A toolkit for transformable materials: How to design materials with reprogrammable shape and function January 20th, 2017

Explaining how 2-D materials break at the atomic level January 20th, 2017

New research helps to meet the challenges of nanotechnology: Research helps to make the most of nanoscale catalytic effects for nanotechnology January 20th, 2017

Display technology/LEDs/SS Lighting/OLEDs

Self-assembling particles brighten future of LED lighting January 18th, 2017

Dressing a metal in various colors: DGIST research developed a technology to coat metal with several nanometers of semiconducting materials January 17th, 2017

Miniscule amounts of impurities in vacuum greatly affecting OLED lifetime December 30th, 2016

Trace metal recombination centers kill LED efficiency: UCSB researchers warn that trace amounts of transition metal impurities act as recombination centers in gallium nitride semiconductors November 3rd, 2016

Chip Technology

Explaining how 2-D materials break at the atomic level January 20th, 2017

New research helps to meet the challenges of nanotechnology: Research helps to make the most of nanoscale catalytic effects for nanotechnology January 20th, 2017

Ultra-precise chip-scale sensor detects unprecedentedly small changes at the nanoscale January 20th, 2017

Nanometrics to Announce Fourth Quarter and Full Year Financial Results on February 7, 2017 January 19th, 2017

Nanoelectronics

Nano-chimneys can cool circuits: Rice University scientists calculate tweaks to graphene would form phonon-friendly cones January 4th, 2017

Advance in intense pulsed light sintering opens door to improved electronics manufacturing December 23rd, 2016

Fast track control accelerates switching of quantum bits December 16th, 2016

GLOBALFOUNDRIES Demonstrates Industry-Leading 56Gbps Long-Reach SerDes on Advanced 14nm FinFET Process Technology: Proven ASIC IP solution will enable significant performance and power efficiency improvements for next-generation high-speed applications December 13th, 2016

Announcements

A big nano boost for solar cells: Kyoto University and Osaka Gas effort doubles current efficiencies January 21st, 2017

A toolkit for transformable materials: How to design materials with reprogrammable shape and function January 20th, 2017

New research helps to meet the challenges of nanotechnology: Research helps to make the most of nanoscale catalytic effects for nanotechnology January 20th, 2017

Ultra-precise chip-scale sensor detects unprecedentedly small changes at the nanoscale January 20th, 2017

Tools

Chemists Cook up New Nanomaterial and Imaging Method: Nanomaterials can store all kinds of things, including energy, drugs and other cargo January 19th, 2017

Nanometrics to Announce Fourth Quarter and Full Year Financial Results on February 7, 2017 January 19th, 2017

Distinguishing truth under the surface: electrostatic or mechanic December 31st, 2016

Nanomechanics Inc. Continues Growth in Revenue and Market Penetration: Leading nanoindentation company reports continued growth in revenues and distribution channels on national and international scales December 27th, 2016

Photonics/Optics/Lasers

Recreating conditions inside stars with compact lasers: Scientists offer a new path to creating the extreme conditions found in stars, using ultra-short laser pulses irradiating nanowires January 12th, 2017

New laser based on unusual physics phenomenon could improve telecommunications, computing January 12th, 2017

Researcher's discovery of new crystal structure holds promise for optoelectronic devices January 6th, 2017

The researchers created a tiny laser using nanoparticles January 5th, 2017

Solar/Photovoltaic

A big nano boost for solar cells: Kyoto University and Osaka Gas effort doubles current efficiencies January 21st, 2017

Chemists Cook up New Nanomaterial and Imaging Method: Nanomaterials can store all kinds of things, including energy, drugs and other cargo January 19th, 2017

Dressing a metal in various colors: DGIST research developed a technology to coat metal with several nanometers of semiconducting materials January 17th, 2017

Stability challenge in perovskite solar cell technology: New research reveals intrinsic instability issues of iodine-containing perovskite solar cells December 26th, 2016

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