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As a new type of quantum state of matter hosting low energy relativistic quasiparticles, Weyl semimetals (WSMs) have attracted significant attention for scientific community and potential quantum device applications. In this study, we present a comprehensive investigation of the structural, magnetic, and transport properties of noncentrosymmetric RAlSi (R = Sm, Ce), which have been predicted to be new magnetic WSM candidates. Both samples exhibit nonsaturated magnetoresistance, with about 900% and 80% for SmAlSi and CeAlSi, respectively, at temperature of 1.8 K and magnetic field of 9 T. The carrier densities of SmAlSi and CeAlSi exhibit remarkable change around magnetic transition temperatures, signifying that the electronic states are sensitive to the magnetic ordering of rare-earth elements. At low temperatures, SmAlSi reveals prominent Shubnikov-de Haas oscillations associated with the nontrivial Berry phase. High-pressure experiments demonstrate that the magnetic order is robust and survival under high pressure. Our results would yield valuable insights into WSM physics and potentials in applications to next-generation spintronic devices in the RAlSi (R = Sm, Ce) family.

GaN-based heterostructures with an InAlGaN/AlGaN composite barrier on sapphire (0001) substrates are grown by a low-pressure metal organic chemical vapor deposition system. Compositions of the InAlGaN layer are determined by x-ray photoelectron spectroscopy, structure and crystal quality of the heterostructures are identified by high resolution x-ray diffraction, surface morphology of the samples are examined by an atomic force microscope, and Hall effect and capacitance-voltage measurements are performed at room temperature to evaluate the electrical properties of heterostructures. The Al/In ratio of the InAlGaN layer is 4.43, which indicates that the InAlGaN quaternary layer is nearly lattice-matched to the GaN channel. Capacitance–voltage results show that there is no parasitic channel formed between the InAlGaN layer and the AlGaN layer. Compared with the InAlGaN/GaN heterostructure, the electrical properties of the InAlGaN/AlGaN/GaN heterostructure are improved obviously. Influences of the thickness of the AlGaN layer on the electrical properties of the heterostructures are studied. With the optimal thickness of the AlGaN layer to be 5 nm, the 2DEG mobility, sheet density and the sheet resistance of the sample is 1889.61 cm2/V s, 1.44 × 1013 cm−2 and as low as 201.1 ω/sq, respectively.

Epitaxial growth of InAlGaN/GaN structures are performed on the c-plane sapphire by pulsed metal organic chemical vapor deposition with different triethylgallium (TEGa) flows in the growth process of InAlGaN quaternary alloys. X-ray photoelectron spectroscopy results show that the Al/In ratio of the samples increases as the TEGa flows increase in the InAlGaN quaternary growth process. High-resolution x-ray diffraction results show that the crystal quality is improved with increasing TEGa flows. Morphology of the InAlGaN/GaN heterostructures is characterized by an atomic force microscopy, and the growth mode of the InAlGaN quaternary shows a 2D island growth mode. The minimum surface roughness is 0.20 nm with the TEGa flows equaling to 3.6 μmol/min in rms. Hall effect measurement results show that the highest electron mobility μ is 1005.49 cm2 /Vs and the maximal two-dimensional electron gas is 1.63 × 1013 cm−2.

Ultra-thin-body (UTB) Ino.53Gao.47As-on-insulator (Ino.53Gao.47As-OI) structures with thicknesses of 8 and 15nm are realized by transferring epitaxially grown Ino.53Gao.47As layers to silicon substrates with 15-nm-thick Al2O3 as a buried oxide by using the direct wafer bonding method. Back gate n-channel metal-oxide-semiconductor field-effect transistors (nMOSFETs) are fabricated by using these Ino.53Gao.47As-OI structures with excellent electrical characteristics. Positive bias temperature instability (PBTI) and hot carrier injection (HCI) characterizations are performed for the Ino.53Gao.47As-OI nMOSFETs. It is confirmed that the Ino.53Gao.47As-OI nMOSFETs with a thinner body thickness suffer from more severe degradations under both PBTI and HCI stresses. Moreover, the different evolutions of the threshold voltage and the saturation current of the UTB Ino.53Gao.47As-OI nMOSFETs may be due to the slow border traps.

A doping technique to fabricate an organic quantum-well electroluminescent device is demonstrated. The fabricated single-quantum-well device consists of the following structure: an N,N'-Bis(3-methyphenyl)-N,N'-diphenylbenzidine layer for hole transportation, an 8-(quinolinolate)-aluminum(Alq) layer for electron transportation and a light emitting layer of Alq doped with 5,6,11,12-tetraphenylnaphthacene(rubrene). The dopant rubrene serves as a potential well, whereas the undoped Alq layer serves as a barrier layer. The efficiency and luminance of the device have been significantly improved. The observed phenomena of the spectral narrowing and the emission peak energy blue-shift are a result of the recombination of carriers from the quantized energy states.

It is still challenging to obtain broadband emission covering visible light spectrum as much as possible with negligible angular dependence. In this work, we demonstrate a low driving voltage top-emitting white organic light-emitting diode (TEWOLED) based on complementary blue and yellow phosphor emitters with negligible angular dependence. The bottom copper anode with medium reflectance, which is compatible with the standard complementary metal oxide semiconductor (CMOS) technology below 0.13 μm, and the semitransparent multilayer Cs2CO3/Al/Cu cathode as a top electrode, are introduced to realize high-performance TEWOLED. Our TEWOLED achieves high efficiencies of 15.4 cd/A and 12.1 lm/W at a practical brightness of 1000 cd/m2 at low voltage of 4 V.

An SF6/CF4 cyclic reactive-ion etching (RIE) method is proposed to suppress the surface roughness and to optimize the morphology of Ge fin, aiming at the fabrication of superior Ge FinFETs for future CMOS technologies. The surface roughness of the Ge after RIE can be sufficiently reduced by introducing SF6-O2 etching steps into the CF4-O2 etching process, while maintaining a relatively large ratio of vertical etching over horizontal etching of the Ge. As a result, an optimized rms roughness of 0.9nm is achieved for Ge surfaces after the SF6/CF4 cyclic etching with a ratio of greater than four for vertical etching over horizontal etching of the Ge, by using a proportion of 60% for SF6-O2 etching steps.

The gate-induced-drain-leakage of MOSFETs is analyzed to better understand the sub-threshold swing degradation of SiGe tunnel field-effect transistors and their band-to-band tunneling mechanism. The numerical model of the analysis is elaborated. Equivalent trap energy levels are extracted for Si and strained SiGe. It is found that the equivalent trap energy level in SiGe is shallower than that in Si.

In kinesin's mechanochemical cycle, ATP's binding to the nucleotide-free leading head is exquisitely gated so that futile hydrolysis is effectively avoided. Experiments show that, when both kinesin heads bind to a microtubule, ATP cannot bind to kinesin's leading head when the neck linker (NL) of this head has a backward orientation. How NL's backward orientation is maintained needs understanding on a structural basis. By using steered molecular dynamics and mutation simulations, we investigate the backward-pointing conformation of the leading head's NL under different inter-head tensions. We find that the NL cannot keep in a strict backward orientation solely by the inter-head tension. LYS325 (amino acid sequence in 2KIN) has an assistant locking function which locks the NL and β0 to the β-domain. This locking function has an enhanced positive cooperation with the inter-head tension. When the inter-head tension is weakened, this locking function can be broken, resulting in a loose backward orientation of the NL. The difference between the strict and loose backward orientation of the NL might be a crucial factor in the gating mechanism. These results are consistent with relevant experiments and proposals.

We report on a white hybrid light-emitting device employing a mixture of ternary CdSe/ZnS quantum dots (QDs) as an emitting layer (EML) and a small molecular material tris(8-hydroxyquinoline) aluminum (Alq3) as an electron-transporting layer. The film morphology of the spin-coated mixture of QDs is strongly improved via thermal annealing, and therefore a close-packed QD-EML is realized between organic charge-transporting layers. As a result, compared to the device with an unannealed QD-EML, the emission of Alq3 is deeply suppressed. In addition, a maximum luminance of more than 1000 cd/m2 and a maximum luminous efficiency of 2.2 cd/A are achieved.

An optical 90° hybrid based on an InP 4 × 4 multimode interference (MMI) coupler is designed and fabricated for the application in a coherent receiver. It reveals that the width of multimode waveguide is the most critical parameter for the devices, and the multimode waveguide width can be accurately controlled within 0.1 μm in our experiments. Across the entire C-band (1527–1561 nm), the maximum imbalance of the devices is less than 0.7 dB, and the common mode rejection ratios for in-phase channels and quadrature channels are better than −24 dB.

Structure of high spin states in 87Zr was studied through the reaction 59Co(32S, 3pn)87Zr at a beam energy of 118 MeV using in-beam γ-ray spectroscopic method. Measurement of γ - γ coincidence was performed, and directional correlation orientation ratios of some γ rays were determined. The level scheme of 87Zr was established up to spin (37/2+) and (43/2-). Many previously unknown states have been observed. Comparison with neighboring isotones indicates that the effect of neutron on nuclear structure property is predominant compared to proton, and there is a tendency of reduction in band crossing frequency with increasing proton number.