A team of Lawrence Berkeley National Laboratory researchers believes it has uncovered the secret behind the unusual optoelectronic properties of single atomic layers of transition metal dichalcogenide (TMDC) materials, the 2-D semiconductors that hold great promise for nanoelectronic and photonic applications.
As a semiconductor material, germanium is superior to silicon. But it is more expensive to process for widespread use in batteries, solar cells, transistors and other applications. Researchers in Missouri have now developed what they call “a simple, one-step method” to grow nanowires of germanium from an aqueous solution. Their process could make it more feasible to use germanium in lithium-ion batteries.
Univ. of Washington researchers have developed what they believe is the thinnest-possible semiconductor, a new class of nanoscale materials made in sheets only three atoms thick. They have demonstrated that two of these single-layer semiconductor materials can be connected in an atomically seamless fashion known as a heterojunction. This result could be the basis for next-generation flexible and transparent computing.
A new argument has just been added to the growing case for graphene being bumped off its pedestal as the next big thing in the high-tech world by the 2-D semiconductors known as MX2 materials. An international collaboration of researchers led by Lawrence Berkeley National Laboratory has reported the first experimental observation of ultrafast charge transfer in photo-excited MX2 materials.
Rice Univ. researchers have created a CMOS-compatible, biomimetic color photodetector that directly responds to red, green and blue light in much the same way the human eye does. The new device uses an aluminum grating that can be added to silicon photodetectors with the silicon microchip industry’s mainstay technology, “complementary metal-oxide semiconductor,” or CMOS.
A research team in Europe has achieved significantly increase in the yield of hydrogen produced by the photocatalytic splitting of water. Their breakthrough in light-driven generation of hydrogen was achieved by using a novel molecular shuttle to enhance charge-carrier transport with semiconductor nanocrystals.
Using a relatively straightforward technique, a team of NIST researchers has created what may be the most highly enriched silicon currently being produced. The material is more than 99.9999% pure silicon-28, with less than 1 part per million (ppm) of the problematic isotope silicon-29. Many quantum computing schemes require isotopically pure silicon, for example to act as a substrate for qubits.
An international team of researchers has taken a significant step towards understanding the fundamental properties of the 2-D material silicene by showing that it can remain stable in the presence of oxygen. In a study published in 2D Materials, the researchers have shown that thick multi-layers of silicene can be isolated from parent material silicon and remain intact when exposed to air for at least 24 hrs.
Univ. College London scientists have discovered a new method to efficiently generate and control currents based on the magnetic nature of electrons in semiconducting materials, offering a new way to develop a new generation of electronic devices. One promising approach to developing new technologies is to exploit the electron’s tiny magnetic moment, or spin.
The Facilities 450mm Consortium (F450C), a partnership of leading nanoelectronics facility companies guiding the effort to design and build the next-generation 450mm computer chip fabrication facilities, has announced it has again increased in size, naming Pfeiffer Vacuum as the twelfth member company to join the consortium.
Applying just the right amount of tension to a chain of carbon atoms can turn it from a metallic conductor to an insulator, according to Rice Univ. scientists. Stretching the material known as carbyne by just 3% can begin to change its properties in ways that engineers might find useful for mechanically activated nanoscale electronics and optics.
One of the major road blocks to the design and development of new, more efficient solar cells may have been cleared. Researchers with the Lawrence Berkeley National Laboratory have developed the first ab initio method for characterizing the properties of “hot carriers” in semiconductors. Hot carriers are electrical charge carriers with significantly higher energy than charge carriers at thermal equilibrium.
Researchers have taken a major stride toward perfectly efficient lighting that is also relatively inexpensive and simple to make. The same material can also reveal the presence of water by changing color. Incandescent bulbs only turn 5% of the electricity they use into light, while fluorescent LEDs can produce light from up to 25% of the electrons that pass through them. Phosphorescent LEDs can turn every electron into a ray of light.
First developed five years ago at Rice Univ., silicon oxide memories are a type of two-terminal, “resistive random-access memory” (RRAM) technology that beats flash memory’s data density by a factor of 50. At Rice, the laboratory of chemist and 2013 R&D Magazine Scientist of the Year James Tour has recently developed a new version of RRAM that Tour believes outperforms more than a dozen competing versions.
Researchers at Pacific Northwest National Laboratory have developed a porous material to replace the graphite traditionally used in a battery's electrodes. Made from silicon, which has more than 10 times the energy storage capacity of graphite, the sponge-like material can help lithium-ion batteries store more energy and run longer on a single charge.
Using graphene ribbons just several atoms across, a group of researchers at the Univ. of Wisconsin-Milwaukee has found a novel way to “tune” the material, causing the extremely efficient conductor of electricity to act as a semiconductor. By imaging the ribbons with scanning-tunneling microscopy, researchers have confirmed how narrow the ribbon width must be. Achieving less than 10 nm in width is a big challenge.
Experiments aimed at devising new types of photodetectors have been triggered by the increasing use of optoelectronic devices. Researchers in China have proposed a new type of infrared photodetector made from zinc oxide and silicon. Its nanoporous nature, synthesized by a simple sol-gel method, allows it to be responsive to infrared wavelengths.
In semiconductor-based components, high mobility of charge-carrying particles is important. In organic materials, however, it is uncertain to what degree the molecular order within the thin films affects the mobility and transport of charge carriers. Using a new imaging method, researchers have shown that thin-film organic semiconductors contain regions of structural disorder that could inhibit the transport of charge and limit efficiency.
Engineers at the Univ. of Arkansas have designed integrated circuits that can survive at temperatures greater than 350 C—or roughly 660 F. The team achieved the higher performance by combining silicon carbide with wide temperature design techniques. In the world of power electronics and integrated circuits, their work represents the first implementation of a number of fundamental analog, digital and mixed-signal blocks.
At the 2014 Symposium on VLSI Technology in Triangle Park, N.C., researchers from the Univ. of California, Santa Barbara introduced the highest-performing class III-V metal-oxide semiconductor field-effect transistors (MOSFETs) yet demonstrated. The new MOSFETs exhibit, in an industry first, on-current, off-current and operating voltage comparable to or exceeding production silicon devices, while also staying relatively compact.
Crystal IS has introduced Optan, the first commercial semiconductor based on native aluminum nitride (AIN) substrates. Optan increases detection sensitivity from monitoring of chemicals in pharma manufacturing to drinking water analysis.
Researchers are reporting key milestones in developing new semiconductors to potentially replace silicon in future computer chips and for applications in flexible electronics. Findings are detailed in three technical papers, including one focusing on a collaboration of researchers from Purdue Univ., Intel Corp. and SEMATECH. The team has demonstrated the potential promise of a 2-D semiconductor called molybdenum disulfide.
Investigated heavily since the 1970s, solar cells have been the great unfulfilled promise for unlimited, almost free energy to power the world. The reasoning is solid: The Earth absorbs almost as much energy per hour than the entire human race uses in a single year.
The basic element of modern electronics, namely the transistor, suffers from significant current leakage. By enveloping a transistor with a shell of piezoelectric material, which distorts when voltage is applied, researchers in the Netherlands were able to reduce this leakage by a factor of five compared to a transistor without this material.
Research published in the Proceedings of the National Academy of Sciences makes it possible to predict how subjecting metals to severe pressure can lower their electrical resistance, a finding that could have applications in computer chips and other materials that could benefit from specific electrical resistance.
A team at Lawrence Berkeley National Laboratory found unexpected traces of water in semiconducting nanocrystals. The water as a source of small ions for the surface of colloidal lead sulfide nanoparticles allowed the team to explain just how the surface of these important particles are passivated, meaning how they achieve an overall balance of positive and negative ions.
- Page 1