Technology | Jan 31, 2011

A Material to Revolutionize Electronics - Small Transistors, LEDs and Solar Cells

A discovery made at EPFL could play an important role in electronics, allowing us to make transistors that are smaller and more energy efficient. Research carried out in the Laboratory of Nanoscale Electronics and Structures (LANES) has revealed that molybdenite, or MoS2, is a very effective semiconductor. This mineral, which is abundant in nature, is often used as an element in steel alloys or as an additive in lubricants. But it had not yet been extensively studied for use in electronics.

100,000 times less energy
“It’s a two-dimensional material, very thin and easy to use in nanotechnology. It has real potential in the fabrication of very small transistors, light-emitting diodes (LEDs) and solar cells,” says EPFL Professor Andras Kis, whose LANES colleagues M. Radisavljevic, Prof. Radenovic et M. Brivio worked with him on the study. He compares its advantages with two other materials: silicon, currently the primary component used in electronic and computer chips, and graphene, whose discovery in 2004 earned University of Manchester physicists André Geim and Konstantin Novoselov the 2010 Nobel Prize in Physics.

One of molybdenite’s advantages is that it is less voluminous that silicon, which is a three-dimensional material. “In a 0.65-nanometer-thick sheet of MoS2, the electrons can move around as easily as in a 2-nanometer-thick sheet of silicon,” explains Kis. “But it’s not currently possible to fabricate a sheet of silicon as thin as a monolayer sheet of MoS2.” Another advantage of molybdenite is that it can be used to make transistors that consume 100,000 times less energy in standby state than traditional silicon transistors. A semi-conductor with a “gap” must be used to turn a transistor on and off, and molybdenite’s 1.8 electron-volt gap is ideal for this purpose.

Better than graphene
In solid-state physics, band theory is a way of representing the energy of electrons in a given material. In semi-conductors, electron-free spaces exist between these bands, the so-called “band gaps.” If the gap is not too small or too large, certain electrons can hop across the gap. It thus offers a greater level of control over the electrical behavior of the material, which can be turned on and off easily.

The existence of this gap in molybdenite also gives it an advantage over graphene. Considered today by many scientists as the electronics material of the future, the “semi-metal” graphene doesn’t have a gap, and it is very difficult to artificially reproduce one in the material.

For further information on the new approach please download this information or contact Professor Andras Kis, Laboratory of Nanoscale Electronics and Structures (LANES), andras.kis@epfl.ch, tel: +41 21 693 39 25

FEATURED

Edison Released Brand New DOB III Series Products

Edison Released Brand New DOB III Series Products The DOB III series increased the efficiency, dimming smoothness also provide ultra- low flicker function (flicker 5% and even 5% during dimming). It is compliant to the 2021 European flicker standard IEC TR61547( PstLM) and to CIE TN006 (SVM) on request. It can be applied in many different lighting ... Read more »

EDITORIAL

Würth Elektronik's Power-Saving WL-SMTW: Colors for Feeding Plants

Würth Elektronik's Power-Saving WL-SMTW: Colors for Feeding Plants SMT mountable LEDs in a 2835 package extend Würth Elektronik extensive range of horticulture LEDs. The three WL-SMTW series LEDs emit light of the wavelengths 450 nm (Deep Blue), 660 nm (Hyper Red) and 730 nm (Far Red) – ideal for applications controlling plant growth through specific light ... Read more »

EDITORIAL

Higher-Performance UV-C Solutions from Lumitronix Feature Nichia's New NCSU334B UVC LED

Higher-Performance UV-C Solutions from Lumitronix Feature Nichia's New NCSU334B UVC LED Following the successful introduction of the first UVC LED modules in August 2020, LED expert Lumitronix from Hechingen is expanding the existing concept of linear module solutions with three new, more powerful versions. These are as well mainly addressed to professional customers who are trained ... Read more »

EDITORIAL

Nexperia Launches Industry-First LED Drivers in DFN Package with Side-Wettable Flanks

Nexperia Launches Industry-First LED Drivers in DFN Package with Side-Wettable Flanks Nexperia, the expert in essential semiconductors, today announced a new range of LED drivers in the space-saving DFN2020D-6 (SOT1118D) package. This case style features side-wettable flanks (SWF) which facilitate the use of AOI (automated optical inspection), and improve reliability. This is the ... Read more »