Intersubband transitions in ZnO∕MgZnO multiple quantum wells (MQWs) are investigated by a photocurrent spectroscopy. Photocurrent peaks observed the energy range from 300to400meV and shifted to higher reducing ZnO well thickness. Polarization-resolved spectra show that these when polarization of incident lights is TM mode, following intersubband selection rule. Calculation indicates transition first third subband MQWs.

We developed a fabrication process of an epitaxial MgAl2O4 barrier for magnetic tunnel junctions (MTJs) using direct sputtering method from spinel sintered target. Annealing the sputter-deposited layer sandwiched between Fe electrodes led to formation (001)-oriented cation-disorder with atomically sharp interfaces and lattice-matching electrodes. A large magnetoresistance ratio up 245% at 297 K (436% 3 K) was achieved in Fe/MgAl2O4/Fe(001) MTJ as well excellent bias voltage dependence. These...

Terahertz frequency has promising applications in communication, security scanning, medical imaging, and industry. THz absorbers are one of the required components for future applications. However, nowadays, obtaining a high absorption, simple structure, ultrathin absorber is challenge. In this work, we present thin that can be easily tuned through whole range (0.1–10 THz) by applying low gate voltage (<1 V). The structure based on cheap abundant materials (MoS2/graphene). Nanoribbons...

Epitaxial Fe/magnesium gallium spinel oxide (MgGa2O4)/Fe(001) magnetic tunnel junctions (MTJs) were fabricated by magnetron sputtering. Tunnel magnetoresistance (TMR) ratio up to 121% at room temperature (196% 4 K) was observed, suggesting a TMR enhancement the coherent tunneling effect in MgGa2O4 barrier. The layer had structure and it showed good lattice matching with Fe layers owing slight tetragonal distortion of MgGa2O4. Barrier thickness dependence resistance current-voltage...

The electric polarization of (Zn, Mg)O alloys, known as stable wide-bandgap semiconductors, is an intrinsic property that has a significant impact on the properties and performance polar ZnO-based optoelectronic devices, such in case quantum-confined Stark effect. Because Wurtzite (WZ)-ZnMgO exhibits high potential for epitaxial growth with tunable bandgap energy, we fabricated high-quality pseudomorphic ZnMgO thin films O-polar ZnO substrates achieved maximum Mg solubility 45%. In addition,...

Although single-crystalline spinel (MgAl2O4)-based magnetic tunnel junctions (MTJs) are known to show a good bias voltage dependence of magnetoresistance (TMR) ratio over MgO-based MTJs, no polycrystalline MgAl2O4-based MTJs exhibiting large TMR ratios have been grown previously due the lack crystallinity MgAl2O4 barrier. In this work, we demonstrate growth polycrystalline-based with exceeding 240% and an improved compared that MTJs. An ultra-thin CoFe/MgO seed layer on amorphous CoFeB...

Malaria is a major public health concern with over 200 million new cases annually, resulting in significant financial costs. Preventive measures and diagnostic remedies are crucial saving lives from malaria, especially developing nations. 2D materials are, therefore, ideal for fighting such an epidemic. Graphene its derivatives extensively studied due to their exceptional properties this case. The biomedical applications of graphene‐based nanomaterials have gained interest recent years...

We investigated the tunneling electroresistance (TER) in metal/wurtzite-MgZnO/metal junctions for applications nonvolatile random-access memories. A resistive switching was detected utilizing an electric-field cooling at ±1 V and exhibited a TER ratio of 360%–490% 2 K. The extracted change average barrier height between two resistance states gave estimation MgZnO electric polarization 2.5 μC/cm2 low-temperature limit. In addition, temperature-dependent shift localized energies interface...

An epitaxial wurtzite (WZ) Mg0.23Zn0.77O barrier based magnetic tunnel junction (MTJ), with electrode-barrier structure of Co0.30Pt0.70 (111)/Mg0.23Zn0.77O (0001)/Co (0001), was fabricated. The good crystallinity and tunneling properties were experimentally confirmed. Electrical investigations demonstrated its high resistance-area product 1.05 MΩ μm2, a maximum magneto-resistance (TMR) 35.5%, the existence localized states within producing TMR rapid decrease oscillation when increasing...

Deposition of ZnO thin films on a ferromagnetic metallic buffer layer (Co3Pt) by molecular beam epitaxy technique was investigated for realization ZnO-based magnetic tunneling junctions with good quality hexagonal as tunnel barriers. For substrate temperature 600 °C, exhibited low oxygen defects and high electrical resistivity 130 Ω cm. This value exceeded that grown sputtering technique, which are used barriers in ZnO-MTJs. Also, the effect flow during deposition epitaxial growth conditions...

Abstract The quantum well (QW) realizes new functionalities due to the discrete electronic energy levels formed in well‐shaped potential. Magnetic tunnel junctions (MTJs) combined with a quasi‐QW structure of Cr/ultrathin‐Fe/MgAl 2 O 4 (001)/Fe, which Cr quasi‐barrier layer confines Δ 1 up‐spin electrons Fe well, are prepared perfectly lattice‐matched interfaces and atomic number control. Resonant peaks clearly observed differential conductance MTJs formation QWs. Furthermore, enhanced...

We investigated the effect of a Mg-Al layer insertion at bottom interface epitaxial Fe/$MgAl_{2}O_{4}$/Fe(001) magnetic tunnel junctions (MTJs) on their spin-dependent transport properties. The magnetoresistance (TMR) ratio and differential conductance spectra for parallel configuration exhibited clear dependence inserted thickness. A slight (thickness < 0.1 nm) was effective obtaining large TMR above 200% room temperature observing distinct local minimum structure in spectra. In contrast,...

The electric control of magnetic anisotropy has important applications for nonvolatile memory and information processing. By first-principles calculations, we show a large in ferromagnetic/ferroelectric CoPt/ZnO interface. Using the switched polarization ZnO, density-of-states at CoPt surface change. Due to strong Co/Pt orbitals hybridization spin-orbit coupling, was found. We experimentally measured change effective by tunneling resistance measurements CoPt/Mg-doped ZnO/Co junctions....

Viral infections are among the main reasons for serious pandemics and contagious infections; hence, they cause thousands of fatalities economic losses annually. In case COVID-19, world economies have shut down months, physical distancing along with drastic changes in social behavior many humans has generated issues all countries. Thus, a rapid, low-cost, sensitive viral detection method is critical to upgrade living standards while exploiting biomedicine, environmental science, bioresearch,...

Malaria infection is a major public health worldwide, with millions of new cases and creating huge direct (an indirect) economic losses annually. Thus, the availability preventive methods diagnostic solutions for malaria critical to save many lives, especially in poor countries. The emergence graphene materials provided researchers promising path variety fields including medical field fight epidemics pandemics. In this contribution, we discuss key-enabling graphene-based technologies against...

Schottky contacts (SC) at the ferromagnet/ZnO interface are good candidates for realization and control of several semiconductor emerging magnetic phenomena such spin injection spin-controlled photonics. In this work, we demonstrate epitaxial growth single-phase wurtzite-ZnO thin films on fcc Pt/Co$_{0.30}$Pt$_{0.70}$ (111) electrodes by MBE technique. While properties buffer remain unchanged after ZnO growth, electric measurements back-to-back diodes revealed a barrier height metal/ZnO...

Ferroelectric memristors have attracted much attention as a type of nonvolatile resistance switching memories in neuromorphic computing, image recognition, and information storage. Their mechanisms been studied several times perovskite complicated materials systems. It was interpreted the modulation carrier transport by polarization control over Schottky barriers. Here, we experimentally report isothermal resistive across CoPt/MgZnO barrier using simple binary semiconductor. The crystal...

Quantum-well (QW) devices have been extensively investigated in semiconductor structures. More recently, spin-polarized QWs were integrated into magnetic tunnel junctions (MTJs). In this work, we demonstrate the spin-based control of quantized states iron $3d$-band QWs, as observed experiments and theoretical calculations. We find that magnetization rotation Fe significantly shifts QW quantization levels, which modulate resonant-tunneling current MTJs, resulting a tunneling anisotropic...

The effect of selenium‐free annealing on cesium fluoride (CsF)‐treated Cu(In,Ga)Se 2 (CIGS) thin films is investigated and their solar cell performance evaluated. Annealing CsF‐treated CIGS changes the surface morphology chemical composition, reduces Urbach energy. However, full benefit reduced energies annealed samples not obtained, because an increased buffer/CIGS interface recombination as a consequence re‐evaporation alkali‐containing layer from region upon annealing. On other hand,...