Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Nanomaterials: Formation in a flash - A new lithography technique enables the production of nanoscale patterns of titania for high-tech applications

The nanoscale titania pattern before and after heat-treatment. © 2012 American Chemical Society
The nanoscale titania pattern before and after heat-treatment.

© 2012 American Chemical Society

Abstract:
Titanium dioxide, or titania, is an inorganic material commonly used as a whitening agent in food and toothpaste. It is also used as one of the main active ingredients in sunscreens. The properties that make titania useful in commercial applications — namely its whitening ability and high refractive index — are now being exploited in a wide range of technological applications.

Nanomaterials: Formation in a flash - A new lithography technique enables the production of nanoscale patterns of titania for high-tech applications

Singapore | Posted on July 6th, 2012

One particular area of interest has been the application of titania in dye-sensitized solar cells — devices that can be used to convert sunlight into electricity. Such application often requires the formation of intricate surface patterns, with the key limiting factors for development being cost and speed of processing. Now, Ramakrishnan Ganesan, Mohammad Saifullah and co-workers at the A*STAR Institute of Materials Research and Engineering have described the use of a technique called step-and-flash imprint lithography (SFIL) to produce such patterns on the nanoscale.

"The precursor method to SFIL is thermal nanoimprint lithography, which is extremely time-consuming as it requires temperature-cycling processes to form a pattern," explains Saifullah. "A mold could be pressed into a heated (and softened) resist material or a liquid precursor could be forced into a mold and then hardened upon heating."

Newer processes eliminate the need for heating by using irradiation with ultraviolet (UV) light to harden the polymer. Although this process may be ideal for organic polymer materials, it is more problematic when using inorganic materials such as titania as the liquid precursor materials are highly viscous and do not spread easily. As a result, the dispensing nozzle may sometimes become blocked.

The chemicals used to make titania can also be unstable in solution, so the team had to identify a mixture of components that offered a combination of stability and low viscosity. "We found that an allyl functionalized titanium complex was stable in combination with other polymer precursors," explains Saifullah. The final component of the mixture is a photoinitiator — which starts the polymerization process upon irradiation with UV light.

The mixture was dispensed onto the surface in the form of droplets, and the mold pressed into place to help the liquid spread. Irradiation with UV light results in hardening of the pattern, after which the mold can be removed. A final heating step burns away the organic material, leaving behind a shrunken version of the original pattern made from titania (see image). Significantly, the aspect ratio of the pattern is maintained after the heat-treatment process.

"Our current method is quite specific to titania, but after tackling this most important material, we hope to develop similar procedures for other inorganic materials," says Saifullah.

The A*STAR-affiliated researchers contributing to this research are from the Institute of Materials Research and Engineering

References:

Ganesan, R. et al. Direct patterning of TiO2 using step-and-flash imprint lithography. ACS Nano 6, 1494-1502 (2012). (Direct link to article below)

####

For more information, please click here

Contacts:
A*STAR Research

Copyright © Agency for Science, Technology and Research (A*STAR)

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 Links

Agency for Science, Technology and Research (A*STAR):

Institute of Materials Research and Engineering:

Link to original article in ACS Nano:

Related News Press

News and information

Getting electrons to move in a semiconductor: Gallium oxide shows high electron mobility, making it promising for better and cheaper devices April 24th, 2018

JPK reports on research of the Mestroni Lab at the University of Colorado Denver which use the JPK NanoWizard® AFM to help in the characterization of cardiomyopathies April 24th, 2018

Organic solar cells reach record efficiency, benchmark for commercialization April 23rd, 2018

Remote-control shoots laser at nano-gold to turn on cancer-killing immune cells April 20th, 2018

Chemistry

Salt boosts creation of 2-D materials: Rice University scientists show how salt lowers reaction temperatures to make novel materials April 18th, 2018

Phononic SEIRA -- enhancing light-molecule interactions via crystal lattice vibrations April 10th, 2018

Design approach developed for important new catalysts for energy conversion and storage: New method could aid in design of pharmaceuticals and optical and data storage materials March 21st, 2018

New 4-D printer could reshape the world we live in March 20th, 2018

Discoveries

Getting electrons to move in a semiconductor: Gallium oxide shows high electron mobility, making it promising for better and cheaper devices April 24th, 2018

JPK reports on research of the Mestroni Lab at the University of Colorado Denver which use the JPK NanoWizard® AFM to help in the characterization of cardiomyopathies April 24th, 2018

Organic solar cells reach record efficiency, benchmark for commercialization April 23rd, 2018

Remote-control shoots laser at nano-gold to turn on cancer-killing immune cells April 20th, 2018

Announcements

Getting electrons to move in a semiconductor: Gallium oxide shows high electron mobility, making it promising for better and cheaper devices April 24th, 2018

JPK reports on research of the Mestroni Lab at the University of Colorado Denver which use the JPK NanoWizard® AFM to help in the characterization of cardiomyopathies April 24th, 2018

Organic solar cells reach record efficiency, benchmark for commercialization April 23rd, 2018

Remote-control shoots laser at nano-gold to turn on cancer-killing immune cells April 20th, 2018

Energy

Organic solar cells reach record efficiency, benchmark for commercialization April 23rd, 2018

Psst! A whispering gallery for light boosts solar cells April 14th, 2018

High efficiency solar power conversion allowed by a novel composite material: A composite thin film developed at INRS improves significantly solar cells' power conversion efficiency April 10th, 2018

Light 'relaxes' crystal to boost solar cell efficiency: Rice, Los Alamos discovery advances case for perovskite-based solar cells April 6th, 2018

Solar/Photovoltaic

Organic solar cells reach record efficiency, benchmark for commercialization April 23rd, 2018

Salt boosts creation of 2-D materials: Rice University scientists show how salt lowers reaction temperatures to make novel materials April 18th, 2018

Psst! A whispering gallery for light boosts solar cells April 14th, 2018

High efficiency solar power conversion allowed by a novel composite material: A composite thin film developed at INRS improves significantly solar cells' power conversion efficiency April 10th, 2018

Printing/Lithography/Inkjet/Inks/Bio-printing

New 4-D printer could reshape the world we live in March 20th, 2018

Leti & Mapper announce cyber-security breakthrough that encrypts individual chips with a code: Low-Cost Cyber-Security Breakthrough that Encrypts Individual Chips With a Unique Code Presented at SPIE Advanced Lithography 2018 in San Jose March 2nd, 2018

Basque researchers turn light upside down February 23rd, 2018

A simple new approach to plastic solar cells: Osaka University researchers intelligently design new highly efficient organic solar cells based on amorphous electronic materials with potential for easy printing January 28th, 2018

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



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project