Gold nanoparticles improve photodetector performance

July 26, 2013

The mineral molybdenum disulfide (MoS2), which, when solid, behaves in many ways like grease, has semiconducting properties that make it a promising alternative to silicon or graphene in electronic devices. It also strongly absorbs visible light, and so it has been widely employed in light-sensing photodetectors, which are used in a wide range of technologies, such as environmental sensing, process control in factories, and optical communication devices.

Researchers at the National University of Singapore have now found a way to boost the performance of MoS2 photodetectors even further—with nanoparticles of gold. They describe this improvement in the journal Applied Physics Letters, which is produced by AIP Publishing.

Wei Chen, an assistant professor of chemistry and physics, along with graduate student Jia Dan Lin, and their colleagues, applied a single, loosely arranged layer of to the top of a MoS2 photodetector. The gold layer, although less than 15 billionths of a meter thick (representing the diameter of each individual nanoparticle) and made up of fewer than 1000 individual particles, improved the photodetectors' efficiency by a factor of three, according to Chen.

"We anticipate orders of magnitude higher improvement of MoS2's sensitivity using a higher density of coated nanoparticles," Chen said.

Chen suspects that the plasmon oscillations (variations in the electron density) of individual nanoparticles—which enhance the local optical field—may be one reason for the improved performance of the photodetectors.

"The next step will focus on varying the materials used to make the nanoparticles, as well as their size, shape, and arrangement," Chen noted—adjustments that will "tune" the plasmon resonance wavelength of the metal nanostructure arrays, making it possible for MoS2 todetect multiple colors for the first time.

Explore further: High efficiency infrared photodetectors using gold nanorods

More information: Applied Physics Letters. DOI: 10.1063/1.4807658

Related Stories

High efficiency infrared photodetectors using gold nanorods

March 25, 2011

Toyohashi Tech researchers develop an innovative infrared photodetector exploiting ‘plasmon resonance’ at the surface of gold nanorods. This technology shows potential as the basis for the development of high efficiency ...

Fantastic flash memory combines graphene and molybdenite

March 19, 2013

Swiss scientists have combined two materials with advantageous electronic properties—graphene and molybdenite—into a flash memory prototype that is very promising in terms of performance, size, flexibility and energy ...

Recommended for you

Electrical circuit made of gel can repair itself

August 25, 2015

(Phys.org)—Scientists have fabricated a flexible electrical circuit that, when cut into two pieces, can repair itself and fully restore its original conductivity. The circuit is made of a new gel that possesses a combination ...

Biological tools create nerve-like polymer network

August 24, 2015

Using a succession of biological mechanisms, Sandia National Laboratories researchers have created linkages of polymer nanotubes that resemble the structure of a nerve, with many out-thrust filaments poised to gather or send ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.