The development of memristive device technologies has reached a level of maturity to enable the design and fabrication of complex and large-scale hybrid memristive-Complementary Metal-Oxide Semiconductor (CMOS) neural processing systems. These systems offer promising solutions for implementing novel in-memory computing architectures for machine learning and data analysis problems. We argue that they

Chirality, handedness, is one of the most fundamental intriguing asymmetries in nature. By definition, chiral objects cannot be superimposed onto each other after mirror reflection operation. Numerous examples of chiral structures can be found in nature, for example, chiral molecules and chiral magnetic nanostructures. Moving electrons are associated with handedness by their own spins due to spin–orbit

The advent of materials with thermally activated delayed fluorescence (TADF) has triggered a wave of research to break the mutual exclusion of high efficiency and long lifetime of blue organic light-emitting diodes. Representatively, multiple donor-acceptor-type carbazole-benzonitrile (CzBN) derivatives have realized the longest device lifetimes in the blue region up to now together with high efficiencies

Neutron scattering techniques provide unique insights into the active layer morphology of organic solar cells. The nanoscale morphology, the thin film vertical composition, and the intermixing on a molecular level, which all strongly have an impact on the performance of organic solar cells, can be probed with neutrons. In addition to the static structure, also fast dynamics occurring in the active

Oxygen vacancies play crucial roles in determining the physical properties of metal oxides, representing important building blocks in many scientific and technological fields due to their unique chemical, physical, and electronic properties. However, oxygen vacancies are often invisible because of their dilute concentrations. Therefore, characterizing and quantifying their presence is of utmost importance

We demonstrate a thin-film flip-chip (TFFC) light-emitting diode (LED) emitting in the ultraviolet B (UVB) at 311 nm, where substrate removal has been achieved by electrochemical etching of a sacrificial Al 0.37 Ga 0.63N layer. The electroluminescence spectrum of the TFFC LED corresponds well to the as-grown LED structure, showing no sign of degradation of structural and optical properties by electrochemical

Ellipsoidal mirrors are promising optical devices for soft x-ray focusing. A fabrication process consisting of master fabrication and replication has been developed to produce ellipsoidal mirrors with wide apertures of approximately 10 mm. In the present study, the focusing performance of an ellipsoidal mirror was evaluated using soft x-rays in the soft x-ray beamline BL25SU-a of SPring-8. The focus

Minimizing recombination at semiconductor surfaces is required for the accurate determination of the bulk carrier lifetime. Proton donors, such as hydrofluoric acid and superacids, are well known to provide highly effective short-term surface passivation. We demonstrate here that aprotic solutions based on bis(trifluoromethanesulfonyl)methane (TFSM) in hexane or pentane can also result in excellent

TiS2 has been intensively studied as an electrode material and a thermoelectric material for energy storage and conversion applications due to its high electrical conductivity. Understanding the influence of defects on electrical transport is of importance not only to resolve the long-standing question concerning the nature of TiS2, but also for the rational design of TiS2 based devices for energy

We have demonstrated an on-wafer fabrication process for AlGaN-based UV-C laser diodes (LDs) with etched mirrors and have achieved lasing for 100 ns pulsed current injection at room temperature. A combined process of dry and wet etching was employed to achieve smooth and vertical AlGaN (1 1 ¯00) facets. These etched facets were then uniformly coated with a distributed Bragg reflector by atomic layer

We report the growth of InSb/CdTe hetero-epitaxial thin films on the GaAs (111)B substrate using molecular beam epitaxy. The use of (111) orientation enables the fast strain relaxation during the CdTe buffer layer growth, and major crystallographic defects are confined near the CdTe/GaAs interface. Owing to the lattice matching between InSb and CdTe, layer-by-layer 2D growth of InSb is observed from

For SiO2/4H–SiC (0001) and (000–1) n-type metal-oxide-semiconductor capacitors, the relationship between flatband voltage and the thickness of oxide was investigated after NO post-oxidation annealing to evaluate the expected flatband voltage (VFB) without a fixed charge effect. After removal of the fixed charge effect, there was an anomalous negative shift of VFB on (0001) 4H–SiC, which would be attributed

The direct bandgap nature of semiconductors is crucial for a wide range of optoelectronic devices and energy applications. These materials are mainly concentrated in hybrid organic–inorganic halide perovskites, III–V semiconductors, and monolayer transition metal dichalcogenides. Here, we report an AA′3B2B′2O12-type direct bandgap semiconductor CaCu3Fe2Ta2O12 using spin-polarized density functional

Magnetic skyrmions are particle-like topological spin configurations, which can carry binary information and thus are promising building blocks for future spintronic devices. In this work, we investigate the relationship between the skyrmion dynamics and the characteristics of injected current in a skyrmion-based spin torque nano-oscillator, where the excitation source is introduced from a point nano-contact

We investigate the transverse response under the out-of-plane magnetic field for magnetic heterostructures with Cu/Bi2O3 or Ag/Bi2O3 Rashba interfaces. We detect opposite contributions on the transverse resistance by the Cu/Bi2O3 and Ag/Bi2O3 interfaces, which interestingly coincide well with the opposite signs of the spin/charge interconversion from the two interfaces. We suppose the opposite influences

We report on an in situ study of oxygen exposure and Mg dusting effects on current-induced magnetization switching in Pt/Co bilayers via controlled oxygen exposure, Co and Mg deposition, and electrical measurements in ultrahigh vacuum. We show that the oxygen exposure and Mg dusting induce changes in saturation magnetization, effective magnetic anisotropy, spin–orbit torque, and switching current density

In this work, undoped semiconductors, germanium (Ge) and germanium tin (GeSn), were grown on ferrimagnetic insulator yttrium iron garnet (YIG) thin films using ultra-high vacuum molecular beam epitaxy. The crystallinity of the structure was determined from x-ray diffraction and high-resolution transmission electron microscopy combined with energy dispersive x-ray spectroscopy. Both spin pumping and

Spin-polarized scanning tunneling microscopy (SP-STM) experiments on ultrathin films with non-collinear spin textures demonstrate that resonant tunneling allows for atomic-scale spin-sensitive imaging in real space at tip-sample distances of up to 8 nm. Spin-polarized resonance states evolving between the foremost atom of a magnetic probe tip and the opposed magnetic surface atom are found to provide

Domain-wall dynamics under strong, super-coercive electric fields in polycrystalline bismuth ferrite (BiFeO3) are not well established due to the experimental difficulties in processing high phase purity perovskite with low electrical conductivity. Overcoming these difficulties, here we present x-ray diffraction measurements carried out in situ during electrical poling with a trapezoidal electric-field

We have investigated the photovoltaic action in a ferroelectric semiconductor SbSI with a potentiometry for a multiterminal device under local laser irradiation. The DC-voltage characteristics indicate that the device characteristics are understood to be equivalent to a series circuit composed of dark-resistances for the unirradiated parts and the parallel circuit of a current source and photo-resistance

A series of Ruddlesden-Popper-type Srn+1VnO3n+1 (n = 1, 2) (001) epitaxial thin films was grown on LaAlO3 and LaSrGaO4 substrates with tensile and compressive epitaxial strains, respectively. The decrease in VO2 stacking layer number n and the increase in the interlayer distance between the (VO2)n layers resulted in metal-to-insulator transition. The sheet conductance of a single (VO2)n layer in Srn+1VnO3n+1

Nanowire crystals of a tantalum nitride phase have been grown from epsilon-tantalum nitride and ammonium halide precursors at high pressures exceeding several gigapascals. Synchrotron x-ray diffraction and Transmission Electron Microscopy (TEM) observations revealed that they had crystallized in an unreported hexagonal structure with lattice parameters of a = 3.050(1) Å and c = 2.909(2) Å. The one-dimensional

We investigate the effect of strain on the two-dimensional electron gas (2DEG) channel in a flexible Al0.25Ga0.75N/GaN high-electron-mobility transistor (HEMT) by mechanical bending to prove the concept of active polarization engineering to create multifunctional electronic and photonic devices made of flexible group III-nitride thin films. The flexible HEMTs are fabricated by a layer-transfer process

A nano-patterning process is reported in this work, which can achieve surface acoustic wave (SAW) devices with an extremely high frequency and a super-high mass sensitivity. An integrated lift-off process with ion beam milling is used to minimize the short-circuiting problem and improve the quality of nanoscale interdigital transducers (IDTs). A specifically designed proximity-effect-correction algorithm

Acoustic waves can act as tweezers to trap and rotate particles without contact, which have promising application in the manipulation of tissues and living cells. Here, we report a realization of acoustic tweezers and motor. The device is fabricated on a silicon chip scaled to manipulate living cells. The silicon chip transfers incident plane ultrasonic waves into a vortex beam, which traps particles

Developments in global pressure and shear sensors are invaluable for flow visualization and force measurement and are indispensable tools for research in fluid mechanics. Here, we introduce a bio-inspired pressure-sensitive film that has high spatial resolution and a wide measurement range. The film is embedded with fluorescent elastic microspheres that emit light under appropriate excitation. These

Supercooling has recently emerged as a highly promising, multi-scale technique for low-temperature preservation of organs and tissues, preventing damaging ice formation while requiring relatively low doses of added cryoprotectants. However, current supercooling techniques are not thermodynamically stable; mild agitations can cause rapid and destructive ice formation throughout the system, rendering

The interaction between an acoustically driven microbubble and a surface is of interest for a variety of applications, such as ultrasound imaging and therapy. Prior investigations have mainly focused on acoustic effects of a rigid boundary, where it was generally observed that the wall increases inertia and reduces the microbubble resonance frequency. Here we investigate the response of a lipid-coated

Separative extended-gate AlGaAs/GaAs high electron mobility transistor (HEMT) biosensors based on the capacitance change strategy are proposed and fabricated. The working mechanism underlying this strategy is clearly clarified via examining the capacitance evolution on biorecognition and the capacitance matching issue between the HEMT and the sensing pad. The fabricated biosensors demonstrate a good

Environmentally friendly and earth abundant Cu2ZnSnS4 (CZTS) based thin films are potential absorbers for next generation photovoltaics. Their optical properties provide the option to be used as upper cells for Si based tandem solar cells, together with a similar structure to Si, triggering interest in investigation of CZTS/Si tandem cells. However, epitaxially growing CZTS on Si can be challenging

We report the application of focused probe ptychography using binary 4D datasets obtained using scanning transmission electron microscopy (STEM). Modern fast pixelated detectors have enabled imaging of individual convergent beam electron diffraction patterns in a STEM raster scan at frame rates in the range of 1000–8000 Hz using conventional counting modes. Changing the bit depth of a counting detector

TATB (1,3,5-triamino-2,4,6-trinitrobenzene) is a powerful explosive whose dynamical behavior is difficult to study because TATB is so insensitive to initiation by shock waves. We used a tabletop microscope equipped with 0–4.5 km/s laser-launched flyer plates to study shock initiation of TATB, which was fabricated in the form of an array of hundreds of plastic-bonded explosive minicharges (X-TATB = 80%

Magnetic information storage has been achieved by controlling and sensing the magnetic moment orientation of nanoscale ferromagnets. Recently, there has been concentrated effort to utilize materials with antiferromagnetic coupling as a storage medium to realize devices that switch faster, are more secure against external magnetic fields, and have higher storage density. Within this class of materials

The compliant behavior of high fill-factor 10 × 10 μm2 square patterned 60–140 nm thick GaN-on-porous-GaN tiles was demonstrated by utilizing porous GaN as a semi-flexible underlayer. High resolution x-ray diffraction measurements showed a larger a-lattice constant of InGaN layers deposited on these patterned GaN-on-porous GaN pseudo-substrates in comparison to those deposited on co-loaded planar GaN-on-sapphire

In this work, the bandgap of CuO (p-type semiconductor) has been engineered from an indirect bandgap of ∼1 eV to a direct bandgap of 4 eV just by tuning the nanostructure morphology and midgap defect states. The absorption in near-infrared (NIR) and visible regions is ordinarily suppressed by controlling the growth parameters. Considering the increasing scope and demand of varying spectral range (UV-C

We propose a method that utilizes optimized probe time delays of 10–35 ps in hybrid femtosecond/picosecond (fs/ps) vibrational coherent anti-Stokes Raman scattering thermometry and obtains maximum temperature sensitivity from 300 to 2500 K. The relationship between temperature sensitivity and the optimal probe time delay can be approximated by a power function. Sensitive measurements at flame temperatures

A hydrogen-terminated diamond (H-terminated diamond) surface supports a two-dimensional (2D) p-type surface conductivity when exposed to the atmosphere, as a result of the surface transfer doping process. The formation of reliable Ohmic contacts that persist to cryogenic temperature is essential for the exploration of quantum transport in the diamond 2D conducting channel. Herein, the contact properties

The investigation of acoustic emission (AE) reveals mixing of avalanche processes in porous 316L stainless steel. One avalanche mechanism relates to the movement of dislocations, the other to crack propagation. Both mechanisms occur under different external tensions: small tension dislodges dislocations while crack propagation occurs at much higher tension close to the mechanical failure point. In

Real-time control of material properties is challenging yet promising for material design and technological applications. Here, we experimentally demonstrated that the strength of a ZnO single crystal could be altered and restored by the rapid response to the switch-on/off of an electron beam. The effect of electron-beam irradiation on the strength of a ZnO single crystal in the presence and absence

We report on optical waveguides produced by a femtosecond laser in 6H–SiC crystals. Their guiding properties have been investigated at a wavelength of 1064 nm, and confocal micro-Raman images have been obtained at an excitation wavelength of 532 nm. The results demonstrate that mode profiles can be tailored by the adjustment of writing parameters, and the blueshift of the spectrum (at around 787.05 cm−1)

Topoelectrical (TE) circuits consisting of capacitors and inductors can be designed to exhibit various Weyl semimetal (WSM) phases in their admittance dispersion. We consider a TE heterojunction circuit consisting of a central region sandwiched by source and drain regions. The energy flux transmission across the heterojunction can be tuned to exhibit perfect transmission near normal incidence (Klein

A cross-point memory architecture will be adopted to make the most of the suitability of resistance change memories for high integration. To achieve this, the development of a selector device that is connected in series to the memory and helps to remove the sneak path current flowing through unselected and half-selected cells is an urgent requirement. In this Letter, we developed a selector based on

A highly crystalline single- or few-layered 2D-MoS2 induces a high dark current, due to which an extremely small photocurrent generated by a few photons can be veiled or distorted. In this report, we show that suppression in the dark current with the enhancement in the photocurrent of a 2D-based photodetector, which is a prerequisite for photoresponse enhancement, can be achieved by constructing an

In this study, polarized reflection and emission spectroscopy was employed in order to describe experimentally and numerically the coherent behavior of surface plasmon phonon polaritons in shallow n-type gallium nitride grating. For the grating with a 1   μm depth and an 11   μm period, polariton coherence was observed measuring the reduction of the linewidth and the redshift of the resonance position

Magnetic insulators (MIs) have attracted great attention because of their low Gilbert damping, long spin transmission length, and no Ohmic loss. In this study, the high quality TbIG films with perpendicular magnetic anisotropy were epitaxially grown on GGG (111) substrates. In TbIG/Pt bilayers, the angular dependence of coercivity is found to obey the Kondorsky model, suggesting the magnetization reversal

We report the experimental observation of the refraction and reflection of propagating magnetostatic spin waves crossing a 90° domain wall (DW). Time-resolved magneto-optical imaging was used to observe the propagation dynamics of magnetostatic spin waves. Due to the magnetization rotation across such a DW, the dispersion relation of magnetostatic spin waves rotates by 90°. This results in a change

Soft magnetic composites (SMCs) are effective as magnetic powder cores in power transformers. Currently, SMCs used in transformers are mostly prepared from NiZn ferrites. One example of this type of material is NiZnCu ferrite, whose working frequency limit is 40 MHz. Above this frequency, its large magnetic loss angle tangent (   tan δ m), approximately equal to 0.29 at 100 MHz, seriously impairs the

Most experiments on ultrafast magnetodynamics have been conducted using the magneto-optical Kerr effect. Here, we compare the Kerr effect's magnetic sensitivity to the spin dynamics measured by photoemission. The magnetization dynamics on an Fe/W(110) thin film are probed by spin-resolved photoemission spectroscopy and the Kerr effect. The results reveal similarities between the spin dynamics at low

Over the last decade, it has been shown that magnetic non-collinearity at an s-wave superconductor/ferromagnet interface is a key ingredient for spin-singlet to spin-triplet pair conversion. This has been verified in several synthetic non-collinear magnetic structures. A magnetically soft and hard ferromagnetic layer combination in a bilayer structure can function as a field tunable non-collinear magnetic

Ferroelectrics with a perovskite structure, exhibiting strong coupling between photons, carriers, and phonons, have been demonstrated to show a strong photostrictive response. Limited by the optical bandgap, most of the reported ferroelectric perovskites respond only to UV light or weakly respond to visible light below 550 nm. Herein, the photostrictive performance of CaCu3Ti4O12 (CCTO) ceramics, with

Ferroelectric materials reveal an ultra-high piezoelectric effect because of their spontaneous polarization and show high potential for applications. At present, the lead-free piezoelectric materials are in a great demand because of their environmentally friendly character, but their performance needs to be improved. Generally, in order to enhance the piezoelectric coefficients, researchers could rely

The controllable biaxial strain is experimentally imposed on α-In2Se3 nanosheets by an electromechanical device. A redshift of Raman spectra is observed from the nanosheets under the strain. The Grüneisen parameter is calculated to analyze the strain effect on the vibrational behavior. Photoluminescence shows a blueshift, which can reach up to 215 meV per 1% strain. Such tunability of optical characteristics

Ferromagnetism in graphene-based materials has attracted much attention because of their potential applications in future spintronic devices. Here, we propose a strategy to induce “single-atom ferromagnetism” in three-dimensional graphene by Cu anchoring, wherein the Cu atoms are isolated with Cu–N4 moieties, as demonstrated by extended x-ray absorption fine structure and spherical aberration correction

We report the direct measurement of record fast switching speeds in GaN/AlN resonant tunneling diodes (RTDs). The devices, grown by plasma-assisted molecular-beam epitaxy, displayed three repeatable negative differential resistance (NDR) regions below a bias of +6 V. A room temperature peak-to-valley current ratio (PVCR) > 2 was observed, which represents a marked improvement over recent reports. Measurements

Encapsulates are, in general, the passive components of any photovoltaic device that provides the required shielding from the externally stimulated degradation. Here we provide comprehensive physical insight depicting a rather non-trivial active nature, in contrast to the supposedly passive, atomic layer deposition (ALD) grown Al2O3 encapsulate layer on the hybrid perovskite [(FA0.83MA0.17)0.95Cs0

In this work, NaEuF4 nanoparticles (NPs) with high dispersity and uniformity were synthesized using a hydrothermal method and introduced into the TiO2 mesoporous layer of perovskite solar cells (PSCs) for testing as high efficiency, downconversion materials. NaEuF4 can convert high-energy photons into low-energy photons for absorption by CH3NH3PbI3 and generation of more electron–hole pairs; we tested

Fixing a diamond containing a high density of Nitrogen-Vacancy (NV) center ensembles on the apex of a multimode optical fiber (MMF) extends the applications of NV-based endoscope sensors. Replacing the normal MMF with a tapered MMF (MMF-taper) has enhanced the fluorescence (FL) collection efficiency from the diamond and achieved a high spatial resolution NV-based endoscope. The MMF-taper's high FL

Unlocking the full potential of passivating contacts, increasingly popular in the silicon solar cell industry, requires determining the minority carrier lifetime. Minor passivation drops limit the functioning of solar cells; however, they are not detected in devices with open-circuit voltages below 700 mV. In this work, simulations and experiments were used to show the effect of localized surface defects

Exploring Sb2Se3 as a photoelectrochemical (PEC) photocathode for water reduction has recently attracted much attention, mainly due to its excellent photophysical properties and perfect band structure matching with water reduction potential. Whereas significant achievements have been made in improving its photocurrent density, the PEC performance remains poor mostly due to the low onset potential or

This Letter proposes ultrathin InP films consisting of annular nanohole arrays (ANAs) for highly efficient solar cells. By tailoring the inner and outer radii of ANAs properly and combining antireflection coating (ZnO) and back-reflector (Ag), the photocurrent generated in the InP based dielectric-semiconductor-metal (DSM) configuration can be increased dramatically by 124.6% with respect to the planar