Articles tagged with "quantum-dots"
On-demand telecom photon source sets record 92% interference
Researchers at the University of Stuttgart have developed a deterministic single-photon source operating in the telecom C-band (around 1550 nanometers) that achieves a record-high photon indistinguishability of nearly 92%. This breakthrough addresses a major challenge in photonic quantum technology: producing on-demand photons that are both identical and compatible with existing fiber-optic communication networks. Prior deterministic sources in this wavelength range had only reached about 72% interference visibility, insufficient for demanding quantum applications, while probabilistic sources, though more indistinguishable, lack synchronization capabilities. The team used indium arsenide quantum dots embedded in indium aluminium gallium arsenide within a circular Bragg grating resonator to enhance photon emission efficiency. They discovered that lattice vibration-mediated excitation minimized noise and preserved photon coherence better than traditional optical pumping. This advancement enables scalable quantum technologies requiring synchronized, indistinguishable photons, such as measurement-based quantum computing and quantum repeaters for long-distance secure communication. By overcoming a decade-old bottleneck
quantum-computingphotonic-technologytelecom-photon-sourcequantum-dotsfiber-optic-communicationquantum-networkingindium-arsenide-materialsQuantum dots doped with manganese show new magnetic capabilities
Researchers at the University of Oklahoma have achieved a significant breakthrough by successfully doping cesium lead bromide (CsPbBr3) quantum dots with manganese, a feat previously considered very challenging. This doping process replaces nearly 40% of lead atoms with manganese ions, transforming the quantum dots’ emission color from blue to a warm orange with near-perfect efficiency. Unlike typical color changes driven by size variation, this shift results from chemical modification. The manganese doping also imparts magnetic properties to the quantum dots, opening new avenues for their application. This advancement could have wide-ranging impacts across multiple industries. The orange light emitted by the doped quantum dots is beneficial for indoor farming and easier on the eyes, while their enhanced optical properties may improve solar cell efficiency. Additionally, the magnetic nature of these dots could enable innovations in medical imaging, spintronics, and communication technologies. Notably, the doped quantum dots show promise as optically controlled qubits for quantum computing, potentially offering greater stability and less interference than
materialsquantum-dotsmanganese-dopingmagnetic-materialssolar-technologyperovskite-nanomaterialsenergy-systemsSnake-inspired tech adds 4K thermal vision to standard cameras
Researchers at the Beijing Institute of Technology have developed a snake-inspired infrared imaging system that enables 4K thermal vision on standard CMOS camera sensors at room temperature and low cost. Drawing inspiration from snakes’ pit organs, which detect heat signatures in darkness, the team created an infrared-to-visible upconverter integrated directly onto a CMOS chip. This innovation overcomes the traditional limitations of infrared imaging, which typically requires expensive materials or bulky cooling systems, by using a “barrier heterojunction” composed of mercury telluride colloidal quantum dots, zinc oxide, and polymer layers to block thermal noise while maintaining sensitivity to short-wave and mid-wave infrared wavelengths without cryogenic cooling. The system achieves 4K resolution (3840 × 2160) with a pixel pitch of 1.55 microns, allowing it to detect thermal distributions, see through silicon wafers, and image environments invisible to conventional sensors. By converting infrared signals into visible photons efficiently, the technology broadens the detectable spectrum by 14
materialsinfrared-imagingCMOS-sensorsquantum-dotsthermal-visionsnake-inspired-technologylow-cost-sensorsPhoton teleportation achieved between two independent quantum dots
Researchers at the University of Stuttgart, in collaboration with partners from the Leibniz Institute for Solid State and Materials Research in Dresden and Saarland University, have successfully demonstrated quantum teleportation between photons emitted by two different quantum dots. This breakthrough addresses a critical challenge in building quantum repeaters, which are essential for extending secure quantum communication over long distances via fiber networks. By using nearly identical quantum dots to generate single photons and entangled photon pairs, and employing quantum frequency converters to align their frequencies, the team achieved a transfer of polarization states with a success rate slightly above 70 percent. This achievement marks the first time quantum information has been teleported between photons from independent quantum dots, a feat previously hindered by the difficulty of producing indistinguishable photons from separate sources. The experiment involved sending one photon through a 10-meter optical fiber to interfere with another, enabling the teleportation process. The work is part of the Quantenrepeater.Net project, a large German research consortium aiming to develop quantum repeat
quantum-dotsquantum-teleportationquantum-communicationquantum-networksquantum-repeaterssemiconductor-materialsphotonicsSolar Cells To Cure Coal Fever With Quantum Dots
The article discusses recent advancements in solar cell technology, particularly focusing on quantum dot solar cells, which are poised to enhance the solar industry despite political efforts favoring coal. Quantum dots are ultra-small semiconductor particles whose optical properties can be precisely tuned, allowing for improved solar energy conversion. Although early quantum dot solar cells had low efficiencies (around 2.9% in 2010), significant progress has been made, with efficiencies reaching 13.4% by early 2024 due to better understanding of quantum dot connectivity, device structures, and defect reduction. While conventional solar cells already surpass 13.4% efficiency, quantum dots offer the potential to lower manufacturing costs and improve efficiency in multi-material solar cells, making solar power even more economical and scalable. A notable development is the partnership between quantum dot startup UbiQD and First Solar to enhance bifacial solar panels, which capture sunlight on both sides. First Solar estimates that applying a thin quantum dot film on the back side of these panels could boost
energysolar-cellsquantum-dotsrenewable-energymaterials-sciencenanotechnologyclean-energyNew Solar Glass Cranks Up Lettuce Crop Yields By Almost 40%
UbiQD, a US startup, has developed an innovative solar glass infused with quantum dots that significantly enhances greenhouse crop yields, particularly for lettuce. Tested by researchers at the University of California – Davis, the "UbiGro" solar glass demonstrated nearly 40% increases in fresh biomass, leaf area, and root length over a full winter growth period. Additionally, plants grown under this glass showed a 41% improvement in light-use efficiency and higher concentrations of essential nutrients such as nitrogen, phosphorus, potassium, magnesium, zinc, and copper. The glass also altered the spectral red:blue light ratio by 61% without reducing photosynthetically active radiation, optimizing the greenhouse microclimate passively and energy-free. The UC-Davis study, published in Materials Today Sustainability, is the first to evaluate quantum dots integrated with passive solar glass, highlighting the potential of this technology to support climate-smart, resilient food production in greenhouses and vertical farms. UbiQD plans to scale commercial applications of this
energysolar-glassquantum-dotsmaterials-sciencesustainable-agriculturegreenhouse-technologyphotoluminescenceUS opens world-first self-driving robot lab for next-gen quantum tech
Researchers at North Carolina State University have developed Rainbow, the world’s first multi-robot self-driving laboratory designed to accelerate the discovery and optimization of quantum dots—semiconductor nanoparticles critical for future technologies like solar cells, LEDs, displays, and quantum devices. This autonomous system integrates multiple robots that prepare chemical precursors, conduct up to 96 simultaneous reactions using miniaturized batch reactors, and perform real-time optical analysis of the products. Guided by machine learning algorithms, Rainbow can independently design and execute up to 1,000 experiments daily, dramatically outpacing traditional human-led research and enabling rapid identification of optimal synthesis recipes based on user-defined target properties. Beyond speed, Rainbow offers deeper scientific insights by exploring a wider range of chemical precursors and ligand structures, which influence the quantum dots’ properties. This flexibility enhances the potential for discovering novel, high-performance materials and understanding the underlying reasons for their effectiveness. Importantly, the platform is designed to empower scientists by automating labor-intensive experimental tasks, allowing researchers
robotquantum-dotsself-driving-labAI-in-chemistrymaterials-discoverysemiconductor-nanoparticlesenergy-materialsWorld's most powerful X-ray laser spots atomic shifts in solar cells
Scientists at the European XFEL research facility have, for the first time, directly observed atomic-scale deformations inside solar cell materials using the world’s most powerful X-ray laser. Led by Johan Bielecki, PhD, the team captured how electron-hole pairs—created when light excites electrons in a solar cell—cause subtle distortions in the atomic lattice of the material. These tiny deformations, previously undetectable, were visualized using femtosecond-scale X-ray pulses, revealing ultrafast interactions between electron-hole pairs and the crystal lattice. The study focused on quantum dots made of cesium, lead, and bromine (CsPbBr3), where these distortions form a state known as an exciton-polaron. The findings are significant because even minimal lattice deformations critically influence the optical and electronic properties of materials used in solar cells, displays, sensors, and potentially quantum computing components. Zhou Shen, PhD, the study’s lead author, emphasized that understanding these
energysolar-cellsmaterials-scienceX-ray-laserquantum-dotsoptoelectronicsatomic-lattice-deformationEuropean quantum scientists flip excitons like light switches
Researchers from the University of Innsbruck, in collaboration with universities in Dortmund, Bayreuth, and Linz, have developed a novel technique to control dark excitons in semiconductor quantum dots using chirped laser pulses and magnetic fields. Excitons are quasiparticles formed when an electron is excited to a higher energy state, leaving behind a positively charged hole; the electron and hole pair orbit each other due to Coulomb attraction. Excitons are categorized as bright or dark based on their interaction with light: bright excitons can absorb or emit photons, while dark excitons, likely due to differing spin configurations, do not interact optically and thus have longer lifetimes, making them promising for energy storage and quantum information applications. The team demonstrated the ability to switch bright excitons into dark excitons and vice versa, effectively using dark excitons as a quantum memory by storing quantum states in a non-radiative form and reactivating them later with laser pulses. This controlled manipulation opens new avenues
materialsquantum-dotsexcitonssemiconductorenergy-storageoptoelectronicsquantum-entanglementHot electrons from quantum dots break tough bonds using 99% less energy
Researchers at the Hong Kong University of Science and Technology (HKUST) have developed a groundbreaking photocatalytic system using manganese-doped CdS/ZnS quantum dots (QDs) that can break strong chemical bonds with 99% less energy than traditional methods. By harnessing a quantum effect known as the two-photon spin-exchange Auger process, these QDs efficiently generate "hot electrons"—high-energy electrons capable of driving challenging reactions previously thought too difficult for light-based catalysis. This approach allows two low-energy photons to combine their energy inside a quantum dot, producing a powerful electron that can cleave tough bonds such as C–Cl, C–Br, C–I, C–O, C–C, and N–S, and perform reductions on molecules with extremely negative potentials (down to −3.4 V vs. SCE). The system notably enables reactions like the Birch reduction, traditionally requiring harsh conditions like liquid ammonia and alkali metals, to proceed under
quantum-dotshot-electronsphotocatalysisnanomaterialsenergy-efficiencychemical-bondsphotoreductionNew robot eyes respond to blinding light 5 times faster than humans
Researchers at Fuzhou University in China have developed a novel machine vision sensor that adapts to extreme lighting conditions about five times faster than the human eye, achieving adaptation in roughly 40 seconds. This sensor uses quantum dots—nano-sized semiconductors that efficiently convert light into electrical signals—engineered to trap and release electric charges in a manner analogous to how human eyes store light-sensitive pigments to adjust to darkness. The device’s layered structure, incorporating lead sulfide quantum dots with polymer and zinc oxide, enables rapid and energy-efficient adaptation to harsh light changes, mimicking key behaviors of human vision. Beyond speed, the sensor improves energy efficiency by filtering visual data at the source, reducing the computational load typical of conventional machine vision systems that process all data indiscriminately. This selective preprocessing is similar to the human retina’s function of focusing on relevant visual information, which could benefit applications like autonomous vehicles and robots operating in variable lighting environments. The research team plans to expand the technology by integrating larger sensor arrays
robotmachine-visionquantum-dotsnanomaterialsautonomous-vehiclesbio-inspired-technologyenergy-efficiency