Science Daily April 3, 2024 Due to the advantages of simple structure and flexibility for energy harvesting, the tube liquid–solid triboelectric nanogenerator (TLS-TENG) has attracted much attention. However, it is limited by low output power due to its low surface charge density and transfer efficiency. Researchers in China proposed and constructed TLS-TENG (SVE-TLS-TENG) with enhanced output performance. Through the space volume effect, the open-circuit voltage (Uoc), short-circuit current (Isc), and transfer charge (Qtc) of SVE-TLS-TENG they improved energy harvesting by 3.5 times, 2.3 times, and 2 times, respectively. The SVE-TLS-TENG has high output performance for harvesting low-frequency and high-entropy motion […]
A single photon emitter deterministically coupled to a topological corner state
Phys.org April 2, 2024 Researchers in China presented a single photon emitter that utilizes a single semiconductor quantum dot, deterministically coupled to a second-order topological corner state in a photonic crystal cavity. By investigating the Purcell enhancement of both single photon count and emission rate within this topological cavity, they got an experimental Purcell factor of Fp = 3.7. They demonstrated the on-demand emission of polarized single photons, with a second-order autocorrelation function g(2)(0) as low as 0.024 ± 0.103. According to the researchers their work may be used for customizing light-matter interactions in topologically nontrivial environments… read more. Open Access TECHNICAL ARTICLE
A solar cell you can bend and soak in water
RIKEN Research March 27, 2024 Waterproofing ultra flexible organic photovoltaics without compromising mechanical flexibility and conformability remains challenging. An international team of researchers (Japan, USA – Georgia Institute of Technology) demonstrated waterproof and ultra flexible organic photovoltaics through the in-situ growth of a hole-transporting layer to strengthen interface adhesion between the active layer and anode by depositing silver electrode directly on top of the active layers, followed by thermal annealing treatment. The in-situ grown hole-transporting layer exhibited higher thermodynamic adhesion between the active layers, resulting in better waterproof. The 3 μm-thick organic photovoltaics retained 89% and 96% of their pristine performance […]
Universal brain-computer interface lets people play games with just their thoughts
Science Daily April 1, 2024 Subject training requires collecting user-specific calibration data due to high inter-subject neural variability that limits the usability of generic decoders. Calibration is cumbersome and may produce inadequate data for building decoders, especially with naïve subjects. Researchers at UT Austin showed that a decoder trained on the data of a single expert is readily transferrable to inexperienced users via domain adaptation techniques allowing calibration-free Brain-computer interface (BCI) training. They introduced two real-time frameworks, (i) Generic Recentering (GR) through unsupervised adaptation and (ii) Personally Assisted Recentering (PAR) and evaluated it on naïve subjects to show that their […]
Breakthrough in light manipulation: Unveiling novel finite barrier bound states
Phys.org March 22, 2024 A boundary mode localized on one side of a finite-size lattice can tunnel to the opposite side which results in unwanted couplings and the tunneling probability decays exponentially with the size of the system which requires many lattice sites before eventually becoming negligibly small. An international team of researchers (USA – PNNL, China) showed that the tunneling probability for some boundary modes can apparently vanish at specific wavevectors and a boundary mode can be completely trapped within very few lattice sites where the bulk bandgap is not even well-defined. The number of trapped states equaled the […]
Top 10 Science and Technology Inventions for the Week of March 29, 2024
01. Electron-bending effect could boost computer memory 02. Moebius rings enable new ways to control light in twisted spaces 03. Quantum interference could lead to smaller, faster, and more energy-efficient transistors 04. Pushing back the limits of optical imaging by processing trillions of frames per second 05. Researchers harness the sun to produce hydrogen gas from water 06. Researchers take major step toward developing next-generation solar cells 07. The world is one step closer to secure quantum communication on a global scale 08. Engineers find a new way to convert carbon dioxide into useful products 09. New research area promotes […]
A 2D ‘antenna’ boosts light emission from carbon nanotubes
Phys.org March 22, 2024 Nanomaterials exhibit excitonic quantum processes occurring at room temperature. However, low dimensionality imposes strict requirements for conventional optical excitation. Researchers in Japan found that exciton transfer in carbon-nanotube/tungsten-diselenide heterostructures occur when alignment could be systematically varied. The mixed-dimensional heterostructures displayed a pronounced exciton reservoir effect where the longer-lifetime excitons within the two-dimensional semiconductor were funneled into carbon nanotubes through diffusion. The new excitation pathway presented several advantages, including larger absorption areas, broadband spectral response, and polarization-independent efficiency. When band alignment was resonant, they observed substantially more efficient excitation via tungsten diselenide compared to direct excitation of […]
Bendable energy storage materials by cool science
Science Daily March 19, 2024 Mesoporous metal oxides exhibit excellent physicochemical properties and are widely used in various fields, including energy storage/conversion, catalysis, and sensors. Although several soft-template approaches are reported, high-temperature calcination for both metal oxide formation and template removal is necessary, which limits direct synthesis on a plastic substrate for flexible devices. Researchers in South Korea developed a universal synthetic approach that combines thermal activation and oxygen plasma to synthesize diverse mesoporous metal oxides (V2O5, V6O13, TiO2, Nb2O5, WO3, and MoO3) at low temperatures (150–200 °C), which could be applied to a flexible polymeric substrate. To demonstrate their […]
Deep Earth electrical grid mystery solved
Science Daily March 20, 2024 Extracellular electron transfer (EET) via microbial nanowires drives important environmental processes and biotechnological applications for bioenergy, bioremediation, and bioelectronics. However, the process is not clear. An international team of researchers (USA – Yale University, Portugal) showed that Geobacter sulfurreducens periplasmic cytochromes PpcABCDE inject electrons directly into OmcS nanowires by binding transiently with differing efficiencies, with the least-abundant cytochrome (PpcC) showing the highest efficiency. This defined nanowire-charging pathway was evolutionarily conserved in phylogenetically diverse bacteria capable of EET. OmcS heme reduction potentials were within 200 mV of each other, with a midpoint 82 mV-higher than reported previously. […]
Electron-bending effect could boost computer memory
Phys.org March 26, 2024 Magnets with a rutile crystal structure may be possible platform for a collinear-antiferromagnetism-induced anomalous Hall effect (AHE). RuO2 is a prototypical candidate material, however the AHE is prohibited at zero field by symmetry. An international team of researchers (Japan, China) showed AHE at zero field in Cr-doped rutile, Ru0.8Cr0.2O2. Their calculations indicated that appropriate doping of Cr at Ru sites reconstructed the collinear antiferromagnetism in RuO2, resulting in a rotation of the Néel vector from [001] to [110] while maintaining a collinear antiferromagnetic state. The AHE with vanishing net moment in the Ru0.8Cr0.2O2 exhibited an orientation […]