By Dexter Johnson:
Quantum dots have offered an attractive option for photovoltaics. Multijunction solar cells made from colloidal quantum dots (CQD) have been able to achieve around 7-percent conversion efficiency in the lab. While figures like this may not seem too impressive when compared to silicon solar cells, their promised theoretical conversion efficiency limit is an eye-popping 45 percent. This is possible because when a single photon is absorbed by a quantum dot, it produces more than one bound electron-hole pair, or exciton, thereby doubling normal conversion efficiency numbers seen in single-junction silicon cells.
Quantum Dot Solar Cells Break Conversion Efficiency Record - [Link]
by Dario Borghino:
Scientists at the Cockrell School of Engineering at the University of Texas have built and tested what appears to be the world’s smallest, fastest, and longest-running nanomotor yet – so small that it could fit inside a single cell. The advance could be used to power nanobots that would deliver specific drugs to individual living cells inside the human body.
In the distant future, when faced with a cancer diagnosis, we might be able to simply ingest a “magic pill” filled with hordes of miniscule nanobots that target individual cancerous cells with drugs and leave the healthy ones unharmed. To power those robots, we need a nanoscale-sized motor that’s capable, sufficiently long-lived, and flexible enough for a wide range of applications.
World’s smallest nanomotor could power cell-sized nanobots for drug delivery - [Link]
Stacking memory is just most obvious application of this ultra-cheap method of stacking 3D circuitry within the metallization layers of standard CMOS chips, but I’m sure that when designers put on their thinking cap they’ll find many more useful applications.: R. Colin Johnson @NextGenLog
Chips On-the-Cheap Funded by SRC – [Link]
Surely everyone remembers their first encounter with silly putty. Knead it into a sphere and it becomes a super bouncy ball, hit it hard and it shatters into pieces that slowly flow together again. Originally developed during the Second World War as a possible substitute for rubber, it is a curiosity, a solution looking for a problem…A team of researchers at the University of California, Riverside Bourns College of Engineering have discovered that the same material can be used in lithium-ion batteries to give them three times the energy storage of a standard cell.
In a paper entitled ‘Stable Cycling of SiO2 Nanotubes as High-Performance Anodes for Lithium-Ion Batteries’ published online in the journal Nature Scientific Reports, the research team describe how using silicon dioxide nanotune anodes in Lithium-ion batteries produced a cell with over three times as much energy storage as a standard Li-ion cell which uses carbon-based anodes. They also found that the silicon dioxide nanotubes remain extremely stable in the battery environment giving the battery a long lifespan. Early results showed no loss of capacity after 100 recharge cycles and the team are confident that it can be cycled many hundreds more times.
Silly Putty boosts Li-ion Energy Density - [Link]
The eye-strain implications alone are staggering.
To promote the upcoming Exceptional Hardware Software Meeting (EHSM) in Hamburg, Germany, a team of DIY artists and scientists has etched the world’s smallest comic strip on a single human hair.
Titled “Juana Knits The Planet,” the strip was created by German artist Claudia Puhlfurst, then carved into the hair using a process called focused ion beam (FIB) etching. “A very sharp and high-speed jet of matter is produced and directed towards the hair to etch it — similar to a fine laser beam,” according to the project’s YouTube page.
Each of the strip’s 12 frames measures in at around 25 micrometers. A micrometer, or micron, is one millionth of a meter. A typical human hair is anywhere from 20 to 200 microns in width.
The second annual EHSM event bills itself as a meeting of international makers, hackers, scientists and engineers aiming to deliver on the “third industrial revolution.” The rest of the conference looks pretty trippy, too.
Among the presentations: electron beam welding, quantum cryptography and the interesting things that happen when molten glass, heated to 1,260 degrees Celcius, hits water. I’ve always been curious about that.
World’s Smallest Comic Strip Etched Onto Human Hair - [Link]
Phys.org has the story on the latest in photovoltaics.
Northwestern University researchers are the first to develop a new solar cell with good efficiency that uses tin instead of lead perovskite as the harvester of light. The low-cost, environmentally friendly solar cell can be made easily using “bench” chemistry—no fancy equipment or hazardous materials.
“This is a breakthrough in taking the lead out of a very promising type of solar cell, called a perovskite,” said Mercouri G. Kanatzidis, an inorganic chemist with expertise in dealing with tin. “Tin is a very viable material, and we have shown the material does work as an efficient solar cell.”
Kanatzidis, who led the research, is the Charles E. and Emma H. Morrison Professor of Chemistry in the Weinberg College of Arts and Sciences.
The new solar cell uses a structure called a perovskite but with tin instead of lead as the light-absorbing material. Lead perovskite has achieved 15 percent efficiency, and tin perovskite should be able to match—and possibly surpass—that. Perovskite solar cells are being touted as the “next big thing in photovoltaics” and have reenergized the field.
Kanatzidis developed, synthesized and analyzed the material. He then turned to Northwestern collaborator and nanoscientist Robert P. H. Chang to help him engineer a solar cell that worked well.
“Our tin-based perovskite layer acts as an efficient sunlight absorber that is sandwiched between two electric charge transport layers for conducting electricity to the outside world,” said Chang, a professor of materials science and engineering at the McCormick School of Engineering and Applied Science.
Environmentally friendly solar cell pushes forward the ‘next big thing in photovoltanics - [Link]
(Phys.org) —A device created by UCLA researchers could lead to a significant leap in the quality of images on smartphones, computer displays, TVs and inkjet printers.
The new material, and a new manufacturing process developed at UCLA, are used to produce semiconductors that are essential to liquid crystal displays and organic light-emitting diode, or OLED, displays.
Led by Yang Yang, the Carol and Lawrence E. Tannas Jr. Professor of Engineering at the UCLA Henry Samueli School of Engineering and Applied Science, the team created a high-performance device that can be produced without requiring a clean room or the expensive equipment now commonly in use.
Device could boost image quality for phones, computers and TVs - [Link]
The world’s thinnest LED at only 3 atoms thick:
Researchers at the University of Washington (UW) have demonstrated electroluminescence in a flexible, mechanically strong construct of the semiconductor tungsten selenide only three atoms thick.
The researchers harvested single sheets of tungsten selenide (WSe2) using adhesive tape, a technique invented for the production of graphene. They used a support and dielectric layer of boron nitride on a base of silicon dioxide on silicon, to come up with the thinnest possible LED.
The LEDs now used in most consumer electronics are rigid and are hundreds to thousands of times as thick as the material being developed at UW — which the team characterizes as 1/10,000th the thickness of a human hair.
Existing inorganic LEDs are not appropriate for use in bendable, foldable applications such as electronic devices and displays integrated into clothing. Organic light-emitting diodes are the usual candidates for such applications, but the techniques being pioneered at UW can produce devices that are not only much thinner — and stackable — but also far more versatile.
UW Researchers Create World’s Thinnest LED At Only 3 Atoms Thick - [Link]