Discovery of a new mechanism for wavelength conversion of light by a plastic material

Sep 18, 2013
The concentration of fluorescent benzoxanthene (Y11) increases in a plastic from left to right, with the sample at the far left being pure plastic with no added molecules. In each sample, ultraviolet light is absorbed and light ranging from blue to green is emitted as a function of the benzoxanthene concentration.

Researchers from the National Institute of Radiological Sciences have discovered a new mechanism for wavelength conversion of emitted light by a plastic material. The results of these studies appeared in Scientific Reports from the Nature Publishing Group on August 26, 2013.

Plastic have been used to covert short wavelength light to longer wavelengths for a wide range of applications, such as and films filtering sunlight for crop cultivation. However, the colour conversion mechanism has not been elucidated in detail. By adding various concentrations a fluorescent molecule to the plastic base substrate, the research team found that new complexed states were formed between the base substrate and the fluorescent molecules at each concentration. In addition, they discovered a new wavelength conversion mechanism in which the initial emitted light is converted in three stages by these complexed states. At high fluorescent molecule concentrations, the wavelength conversion can be extended to the ultraviolet region.

These results are expected to impact industrial technologies, such as the conversion and/or blocking of ultraviolet light, noise reduction in , and improved efficiency in crop cultivation.

In order to resolve the mismatch in the detection or absorption sensitivity by an object for light emitted from a short wavelength source, a with low concentrations of fluorescent molecules can convert the to longer, more useful wavelengths. However, because the light conversion mechanism is not thoroughly understood, breakthroughs in material development and applications have stagnated.

As shown in Figure, Dr. Nakamura et al. synthesised a high purity plastic and investigated the responses to light as a function of concentration of the fluorescent molecule benzoxanthene (Y11). It was discovered that a different complexed state is formed between the plastic base substrate and the fluorescent molecules at different concentrations. For each complexed state, a new wavelength conversion mechanism for light was found. The mechanisms are based on three distinct conversion stages, which extend to the ultraviolet region.

Since this research elucidated a new mechanism involved in of light in a plastic, it is now possible to develop materials utilising this kind of mechanism for converting wavelengths for specific purposes. As a result, the range of applications can be expected to expand to optical technologies, electronics, materials, and agriculture.

Explore further: Wideband wavelength conversion using cavity optomechanics

More information: Nakamura, H. et al. Mechanism of wavelength conversion in polystyrene doped with benzoxanthene: emergence of a complex, Sci. Rep. 3, 2502; (2013). dx.doi.org/10.1038/srep02502

add to favorites email to friend print save as pdf

Related Stories

Graphene photodetector integrated into computer chip

Sep 16, 2013

The novel material graphene and its technological applications are studied at the Vienna University of Technology. Now scientists succeeded in combining graphene light detectors with semiconductor chips.

The fluorescent future of solar cells

May 09, 2013

(Phys.org) —For some solar cells, the future may be fluorescent. Scientists at Yale have improved the ability of a promising type of solar cell to absorb light and convert it into electrical power by adding ...

Recommended for you

New approach to form non-equilibrium structures

16 hours ago

Although most natural and synthetic processes prefer to settle into equilibrium—a state of unchanging balance without potential or energy—it is within the realm of non-equilibrium conditions where new possibilities lie. ...

Nike krypton laser achieves spot in Guinness World Records

18 hours ago

A set of experiments conducted on the Nike krypton fluoride (KrF) laser at the U.S. Naval Research Laboratory (NRL) nearly five years ago has, at long last, earned the coveted Guinness World Records title for achieving "Highest ...

Chemist develops X-ray vision for quality assurance

22 hours ago

It is seldom sufficient to read the declaration of contents if you need to know precisely what substances a product contains. In fact, to do this you need to be a highly skilled chemist or to have genuine ...

The future of ultrashort laser pulses

22 hours ago

Rapid advances in techniques for the creation of ultra-short laser pulses promise to boost our knowledge of electron motions to an unprecedented level.

IHEP in China has ambitions for Higgs factory

Jul 23, 2014

Who will lay claim to having the world's largest particle smasher?. Could China become the collider capital of the world? Questions tease answers, following a news story in Nature on Tuesday. Proposals for ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

vidyunmaya
1 / 5 (3) Sep 20, 2013
Sub: useful data
3 Tier and Three mode Spread functional Index- outlined in my projections- Space cosmology Ineterlinks- vedas.
vidyardhicosmology [dot]blogspot [dot]in/2011/10/light-flow-interaction-plasma-vision [dot]html