Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Photonics: Think thin, think vibrant

Flat panel displays and many digital devices require thin, efficient and low-cost light-emitters for applications. The pixels that make up the different colors on the display are typically wired to complex electronic circuits, but now researchers at A*STAR have developed a display technology that requires a much simpler architecture for operation.

Flat panel displays, mobile phones and many digital devices require thin, efficient and low-cost light-emitters for applications. The pixels that make up the different colors on the display are typically wired to complex electronic circuits that control their operation.

Schematic of the tunable color filter. The combination of a gold film with ring-shaped holes and the use of liquid crystals (red and green) enables pixels of a defined color that can be turned on and off. © 2012 Y. J. Liu

Jing Hua Teng at the A*STAR Institute of Materials Research and Engineering and co-workers have now developed a display technology that requires a much simpler architecture for operation. They demonstrated that combining a thin perforated gold film with a liquid crystal layer is all that it takes to make an efficient color filter.

“Our color filters are a lot thinner and more compact than conventional thin-film-based color filters,” says Teng. “The colors of these filters can be tuned with ease so they are very versatile in applications.”

The color selection of the devices comes from the patterned gold film. The collective motions of the electrons on the film surface — the so-called surface plasmons — absorb light at wavelengths that depend on the details of these patterns. In the present case, the patterns are narrow, nanometer-sized rings cut out of the films (see image). As the diameter of the rings changes, so does the color of the metal film. Pixels of a different color can be realized simply by patterning rings of different sizes across the same gold film.

To realize a full display, however, each of these pixels needs to be turned on and off individually. This is where liquid crystals come in.

Liquid crystals are molecules that can be switched between two different states by external stimuli, such as ultraviolet light. In their normal state the crystals let visible light pass through so that the pixel is turned on. But when ultraviolet is also present, the structure of the liquid crystal molecules will change so that it absorbs visible light (i.e. the pixel is turned off). This process can be repeated over many cycles without degrading the device itself.

Although the device works in principle, it remains a concept on the drawing board for now. This is because there are still many issues that need to be overcome, for example, the optimization of the switching speed and the contrast between ‘on’ and ‘off’ states. In future work, the researchers will need to extend their ideas so that their device can serve a larger area and produce the fundamental colors red, green and blue.

Teng and his team are quite optimistic that they will achieve this soon.

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


Liu, Y. J., Si, G. Y., Leong, E. S. P., Xiang, N., Danner, A. J. & Teng, J. H. Light-driven plasmonic color filters by overlaying photoresponsive liquid crystals on gold annular aperture arrays. Advanced Materials 24, OP131–OP135 (2012).

A*STAR Research | Research asia research news
Further information:

More articles from Materials Sciences:

nachricht From ancient fossils to future cars
21.10.2016 | University of California - Riverside

nachricht Study explains strength gap between graphene, carbon fiber
20.10.2016 | Rice University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>