Molybdenite diodes that can emit light or absorb it to produce electricity

Apr 25, 2014 by Sarah Perrin
The magic of Molybdenite: solar cells and light-emitting diodes
Credit: EPFL

After using it to develop a computer chip, flash memory device and photographic sensor, EPFL scientists have once again tapped into the electronic potential of molybdenite (MoS2) by creating diodes that can emit light or absorb it to produce electricity.

Molybdenite has a few surprises still up its sleeve. After having used it to build an , a flash memory device and a photographic sensor, EPFL professor Andras Kis and his team in the Laboratory of Nanoscale Electronics and Structures (LANES) is continuing his study of this promising semi-conductor. In research recently published in the journal ACS Nano, they have demonstrated the possibility of creating light-emitting diodes and .

The scientists built several prototypes of diodes – in which voltage flows in only one direction – made up of a layer of superposed on a layer of silicon. At the interface, each electron emitted by the MoS2 combines with a "hole" – a space left vacant by an electron – in the silicon. The two elements lose their respective energies, which then transforms into photons. "This light production is caused by the specific properties of molybdenite," explains Kis. "Other semi-conductors would tend to transform this energy into heat."

Even better, by inversing the device, electricity can be produced from light. The principle is the same: when a photon reaches the molybdenite, it ejects an electron, thus creating a "hole" and generating voltage. "The diode works like a solar cell," says Kis. "Our tests showed an efficiency of more than 4%. Molybdenite and silicon are truly working in tandem here. The MoS2 is more efficient in the visible wavelengths of the spectrum, and silicon works more in the infrared range, thus the two working together cover the largest possible spectral range."

Credit: EPFL

The scientists want to study the possibility of building electroluminescent diodes and bulbs. This discovery could, above all, reduce the dissipation of energy in electronic devices such as microprocessors, by replacing copper wires used for transmitting data with light-emitters.

Explore further: Researchers develop first single-molecule LED

add to favorites email to friend print save as pdf

Related Stories

Fantastic flash memory combines graphene and molybdenite

Mar 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 ...

An ultrasensitive molybdenum-based image sensor

Jun 12, 2013

A new material has the potential to improve the sensitivity of photographic image sensors by a factor of five. In 2011, an EPFL team led by Andras Kis discovered the amazing semi-conducting properties of ...

First molybdenite microchip

Dec 05, 2011

(PhysOrg.com) -- Molybdenite, a new and very promising material, can surpass the physical limits of silicon. EPFL scientists have proven this by making the first molybdenite microchip, with smaller and more ...

Researchers develop first single-molecule LED

Feb 03, 2014

The ultimate challenge in the race to miniaturize light emitting diodes (LED) has now been met: a team led by the Institut de Physique et de Chimie des Matériaux de Strasbourg has developed the first ever ...

Recommended for you

For electronics beyond silicon, a new contender emerges

Sep 16, 2014

Silicon has few serious competitors as the material of choice in the electronics industry. Yet transistors, the switchable valves that control the flow of electrons in a circuit, cannot simply keep shrinking ...

Making quantum dots glow brighter

Sep 16, 2014

Researchers from the University of Alabama in Huntsville and the University of Oklahoma have found a new way to control the properties of quantum dots, those tiny chunks of semiconductor material that glow ...

The future face of molecular electronics

Sep 16, 2014

The emerging field of molecular electronics could take our definition of portable to the next level, enabling the construction of tiny circuits from molecular components. In these highly efficient devices, ...

Study sheds new light on why batteries go bad

Sep 14, 2014

A comprehensive look at how tiny particles in a lithium ion battery electrode behave shows that rapid-charging the battery and using it to do high-power, rapidly draining work may not be as damaging as researchers ...

User comments : 0