The most familiar photovoltaic (PV) designs use rigid layers of silicon crystal, but recently inexpensive organic semiconductor materials have also been used successfully. At this time, organic PV devices are hindered by low efficiency, in part because quantifying their electrical properties is a challenge. Researchers have now developed a method that allows the prediction of the current density-voltage curve of a photovoltaic device.
Recent experiments have confirmed that a technique developed several years ago at NIST can enable optical microscopes to measure the 3-D shape of objects at nanometer-scale resolution—far below the normal resolution limit for optical microscopy (about 250 nm for green light). The results could make the technique a useful quality control tool in the manufacture of nanoscale devices such as next-generation microchips.
Just as diamonds with perfect symmetry may be unusually brilliant jewels, the quantum world has a symmetrical splendor of high scientific value. Confirming this exotic quantum physics theory, JILA physicists have observed the first direct evidence of symmetry in the magnetic properties—or nuclear “spins”—of atoms.
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.
To make a better optical fiber for transmitting laser beams, the first idea that comes to mind is probably not a nice long hydrogen bath. And yet, scientists have known for years that hydrogen can alter the performance of optical fibers, which are often used to transmit or even generate laser light in optical devices. Researchers at NIST have put this hydrogen “cure” to practical use.
Physicists at NIST have demonstrated a pas de deux of atomic ions that combines the fine choreography of dance with precise individual control. NIST’s ion duet is a component for a flexible quantum simulator that could be scaled up in size and configured to model quantum systems of a complexity that overwhelms traditional computer simulations.
A hidden hazard lurks beneath many of the roughly 156,000 gas stations across the U.S. The hazard is corrosion in parts of underground gas storage tanks. In recent years, field inspectors in nine states have reported many rapidly corroding gas storage tank components such as sump pumps.
Researchers from NIST and California Institute of Technology (Caltech) have demonstrated a new design for an atomic clock that is based on a chip-scale frequency comb, or a microcomb. The microcomb clock, featured in Optica, is the first demonstration of all-optical control of the microcomb, and its accurate conversion of optical frequencies to lower microwave frequencies.
A research team from NIST, working with the Cleveland Clinic, has demonstrated a dramatically improved technique for analyzing biological cells and tissues based on characteristic molecular vibration "signatures." The new NIST technique is an advanced form of the widely used spontaneous Raman spectroscopy, but one that delivers signals that are 10,000 times stronger than obtained from spontaneous Raman scattering.
Vibrate a solution of rod-shaped metal nanoparticles in water with ultrasound and they'll spin around their long axes like tiny drill bits. Why? No one yet knows exactly. But researchers at the NIST have clocked their speed, and it's fast. At up to 150,000 revolutions per minute, these nanomotors rotate 10 times faster than any nanoscale object submerged in liquid ever reported.
NIST has issued for public review and comment a draft report summarizing 65 challenges that cloud computing poses to forensics investigators who uncover, gather, examine and interpret digital evidence to help solve crimes. The report was prepared by the NIST Cloud Computing Forensic Science Working Group, an international body of cloud and digital forensic experts from industry, government and academia.
The light-warping structures known as metamaterials have a new trick in their ever-expanding repertoire. Researchers at NIST have built a silver, glass and chromium nanostructure that can all but stop visible light cold in one direction while giving it a pass in the other. The device could someday play a role in optical information processing and in novel biosensing devices.
Despite five months of below-average temperatures and twice the normal amount of snowfall, NIST's Net-Zero Energy Residential Test Facility (NZERTF) in Washington, D.C. ended its one-year test run with 491 KW-h of extra energy. Instead of paying almost $4,400 for electricity, the experimental all-electric house actually earned a credit by exporting surplus energy to the local utility.
By combining advanced mathematics with high-performance computing, scientists have developed a tool that allowed them to calculate a fundamental property of most atoms on the periodic table to historic accuracy, reducing error by a factor of a thousand in many cases. The technique also could be used to determine a host of other atomic properties important in fields like nuclear medicine and astrophysics.
A research group at NIST has demonstrated a new method for detecting ignitable liquids that could change the way arson fires are investigated. The new process for analyzing debris for traces of fire accelerants is faster and more accurate than conventional methods and produces less waste.
Imaging and mapping of electric fields at radio frequencies (RF) currently requires the use of metallic structures such as dipoles, probes and reference antennas. To make such measurements efficiently, the size of these structures needs to be on the order of the wavelength of the RF fields to be mapped. This poses practical limitations on the smallest features that can be measured.
Particles of soot floating through the air and comets hurtling through space have at least one thing in common: 0.36. That, reports a research group at NIST, is the measure of how dense they will get under normal conditions, and it’s a value that seems to be constant for similar aggregates across an impressively wide size range from nanometers to tens of meters. NIST hopes the results will aid climate researchers.
Whip together an industrial waste product and a bit of plastic and you might have the recipe for the next revolution in battery technology. Scientists have combined common ingredients to make an inexpensive, high-capacity lithium-sulfur battery that can be cycled hundreds of times without losing function.
A porous material invented by the Rice Univ. lab of chemist James Tour sequesters carbon dioxide, a greenhouse gas, at ambient temperature with pressure provided by the wellhead and lets it go once the pressure is released. The material shows promise to replace more costly and energy-intensive processes.
Heading into the final stretch of a year-long trial run, the experimental net-zero energy house at NIST in Gaithersburg, Md., must overcome an energy deficit of 154 kWhr—equivalent to about $20—during the month of June. The facility was designed to produce at least as much energy as it consumes over the course of a year.
Scientists at NIST and the Joint Quantum Institute have shown how attempts to "push" part of a light beam past the speed of light results in the loss of the quantum data the light carries. The results could clarify how noise might limit the transfer of information in quantum computers.
Researchers at NIST have developed a laser-based instrument that generates artificial sunlight to help test solar cell properties and find ways to boost their efficiency. The novel NIST system simulates sunlight well across a broad spectrum of visible to infrared light. More flexible than conventional solar simulators, the laser instrument can be focused down to a small beam spot and shaped to match any desired spectral profile.
In response to requests from the semiconductor industry, a team of researchers at the Physical Measurement Laboratory has demonstrated that atomic force microscope probe tips made from its near-perfect gallium nitride nanowires are superior in many respects to standard silicon or platinum tips. They also found a way to use the tips as LEDs to illuminate sample regions while scanning.
A chip-scale device that both produces and detects a specialized gas used in biomedical analysis and medical imaging has been built and demonstrated at NIST. Described in Nature Communications, the new microfluidic chip produces polarized (or magnetized) xenon gas and then detects even the faintest magnetic signals from the gas.
Automated guided vehicles—or AGVs—are robotic versions of draft animals, hauling heavy loads and navigating their way in factories, distribution centers, ports and other facilities. These modern beasts of burden are evolving so rapidly in capabilities and electronic intelligence that the need for the equivalent of standardized performance testing has become apriority for the fast-growing AGV industry and its customers.