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Controlling or eliminating the extrinsic interfacial effects is an important concern in the studies of two-dimensional van der Waals (2D vdW) heterostructures. In this Letter, by using WSe2/BN as a model, the annealing effect on the elimination of extrinsic interfacial effects in 2D vdW heterostructures was studied. The formation of the WSe2/BN interface can generate interfacial defects and significantly regulate the type and peak intensity percentage of WSe2 photoluminescence (PL) peak. It is intriguing to find that the thermal annealing effect on the optical property is opposite to that from extrinsic defects. By optimizing the annealing temperature, the PL of the functional-layer WSe2 in the heterostructure is gradually restored. This finding demonstrates that the thermal annealing can efficiently minimize the extrinsic interfacial effects, which may provide a simple and low-cost route to fabricate high-quality 2D vdW devices.

Hexagonal boron nitride (hBN) has drawn great attention for its versatile applications in electronics and photonics, and precise estimation of its thickness is critical in many situations. We propose a rapid and broad range (10–500 nm) in situ thickness estimation method for transparent hBN and SiO2 layers on the Si substrate using Raman peak intensity ratios at two wavenumbers and optical microscopy image analysis. We theoretically and experimentally demonstrate our method for a wide range of hBN layer thicknesses, and the estimated results show excellent agreement with the measured results with a percentile estimation error of 2.5%.

We report the observation of collisions between mutually incoherent, one‐dimensional, bright, steady‐state photorefractive screening solitons. Using the theory of planar dielectric waveguides together with the theory of photorefractive screening solitons, we explain how the collisions depend on the peak intensity of the solitons and the externally applied biased field. Finally, we compare the experimental results with direct numerical simulations.

Magneto‐optical (MO) spectroscopic studies were carried out on submonatomic layer coverage of Co atoms deposited on the reconstructed Au(111) surface forming two‐dimensional lattice of nanometer scaled Co dots. The MO spectral features were considerably affected by the shape of the Co dots. Strong dependence of the MO peak intensity on the change of the Co dot shape was observed at around the plasma edge of Au.

In situ high‐temperature x‐ray measurements have been used to follow the crystallographic changes that occur as Pb‐doped Bi2Sr2Ca1Cu2O8+δ plus other phases transform to Bi2Sr2Ca2Cu3O10+δ in a powder‐in‐tube process for forming tape conductors. On the initial ramp to the reaction temperature, the Bi2Sr2Ca1Cu2O8+δ x‐ray lines first diminish in amplitude, by about a factor of 2 or more, and then begin to grow again above 700 °C. In the 790–795 °C range, a transient new phase is seen. Finally, at temperatures as low as 790 °C, the Bi2Sr2Ca2Cu3O10+δ phase begins to grow as the Pb‐doped Bi2Sr2Ca1Cu2O8+δ disappears. Separate studies of a Pb‐doped Bi2Sr2Ca1Cu2O8+δ pellet without the Ca2Cu1O3 and CuO present show essentially the same peak intensity changes during the temperature ramp to 700 °C.

High‐resolution x‐ray analysis of Si delta‐doped GaAs grown by molecular‐beam epitaxy at a low substrate temperature (230 °C) is presented. Superlattice satellite peaks in the rocking curve are observed for the sample annealed at 700 °C for 10 min. The peak intensity increases with increasing postgrowth annealing temperature and reaches the maximum value for the 900 °C annealed sample. The evolution of the x‐ray rocking curves can be explained consistently by the formation of a GaAs/As superlattice during the annealing period based on the transmission electron microscope observations.

Temperature-dependent photoluminescence (PL) study has been conducted in Ge1−xSnx films with Sn compositions of 0.9%, 3.2%, and 6.0% grown on Si. The competing between the direct and indirect bandgap transitions was clearly observed. The relative peak intensity of direct transition with respect to the indirect transition increases with an increase in temperature, indicating the direct transition dominates the PL at high temperature. Furthermore, as Sn composition increases, a progressive enhancement of direct transition was observed due to the reduction of direct-indirect valley separation, which experimentally confirms that the Ge1−xSnx could become the group IV-based direct bandgap material grown on Si by increasing the Sn content.

We proposed that a fluorescent microsphere with diameter of 6 μm was manipulated into a microtube with inner diameter of 6.2 μm. The whispering gallery modes (WGMs) of fluorescence resonance were observed by 532 nm laser pumping the microspheres-mircotube system. Another microsphere with the same diameter was manipulated into the microtube and mode splitting in the system of two spheres in contact in the mircotube was demonstrated. We also discussed relationship between WGMs peak intensity and the excitation power. The scheme will bring more insight into the applications of WGMs for biomedical diagnostics and microfluidics.

Surface-enhanced Raman scattering intensity versus the separation of 100 nm diameter Au nanopost array on Si substrate was investigated. The relative Raman peak intensity per nanopost at different Raman modes rapidly decreases in a similar manner with the increase in the separation. This experimental result agrees well with the localized electric field enhancement calculation by three dimensional finite-difference time-domain method. The Raman peak intensity is mainly due to the edge enhancement of the nanopost through the coupling effect, and the nonenhancement contribution from the top of the nanopost also plays an important role.

Structural stability of Ti alloy, stabilized as a mixture of bcc (β) and hcp (α) phases, was investigated up to 71GPa. Over this pressure, β phase remains stable, while for α phase, a decrease in c∕a ratio from 1.601 at ambient pressure to 1.568 at 36GPa is observed, followed by an increase to 1.613 at 44GPa. A steady value is then observed up to 67GPa. Above 58GPa, the authors also observe that α phase peak intensity is decreasing. At 67GPa, the authors only observe β phase peaks, which indicates that α→β structural phase transition is complete.

Cubic BN films with a pure cubic phase upper layer were prepared by plasma-enhanced chemical vapor deposition. Infrared spectroscopy was applied to analyze the content of initial sp2-bonded BN layer in cubic BN thin films under compressive stress. It was found that the peak intensity near 1380cm−1 attributed to the B–N stretching vibration of sp2-bonded BN was suppressed by the compressive stress in cubic BN films. The deviation between the measured and calculated peak intensities was found to be linear with the compressive stress when the upper layer of the film is a pure cubic phase layer.

First‐order soliton pulses of 77–250 fs duration have been generated in the wavelength region from 1.37 to 1.49 μm. These solitons are formed by transmitting dye laser pulses at 1.34 μm of 1 ps duration and peak intensity of ≊0.66 GW/cm2 through optical single mode fibers. Soliton narrowing and soliton self‐frequency shift are the dominant shaping mechanisms.

For silica (pure and synthetic) optical fibers, on which tensile stresses from 0 to 4 GPa were imposed, Raman studies were carried out. It has become evident by deconvoluting the silica Raman peaks that the main peak intensity at 440 cm−1 decreases with increasing stress while the peaks at 490, 604, and 800 cm−1 remain practically unchanged. The fact that the 490 cm−1 defect line was not affected by the stress applied to fibers is contrary to the conclusion by G. E. Walrafen, P. N. Krishnan, and S. W. Freiman [J. Appl. Phys. 52, 2832 (1981)]. The results obtained in the present study are rather extensively discussed from a microscopic view of silica glass networks.

The surface scattering of MeV He+ ions channeled along Si〈100〉 from clean well‐characterized Si(100) surfaces is measured. The surface peak intensity, along with other values in the literature, is shown to obey simple scaling laws. For the study of very thin films by backscattering the contribution made by this surface scattering can be important.

Neutron diffraction measurements were made on artificial superlattices of CoO‐NiO, (CoO)m(NiO)n×l prepared on the (0001) surface of α‐Al2O3. (111) layers of CoO and NiO, each less than 2 nm thick (2≤m,n≤8), were stacked alternatively to a total thickness of less than 70 nm (m+n≤15,l≤25). A well‐defined magnetic Bragg peak indexed as (1/2 1/2 1/2) was observed for all the samples, and a magnetic structure of type FCC2 with the spin axis lying in the (111) planes grown was suggested. The temperature dependence of the magnetic peak intensity revealed a sharp, single magnetic transition. The Neel temperature was found to vary as a linear function of n/(m+n).