The structural and optical properties of GaAs1−xBix alloys for x up to 0.108 have been investigated by high resolution X‐ray diffraction and photoluminescence (PL). At room temperature (RT), the PL intensity of the GaAs0.97Bi0.03 sample was found to be ∼300 times higher than a GaAs control sample grown at the same temperature (400 °C). PL measurements carried out at 10 K show that when excitation power, Pex was increased from 0.11 to 1140 W cm−2, the PL peak energy blue‐shifts by 80 meV while the full‐width‐at‐half‐maximum reduces from 115 to 63 meV. However, the PL peak emission energy becomes independent of the excitation power at RT. The results indicate the presence of localized energy states in the GaAs0.97Bi0.03 sample, which trap carriers at low temperatures and that the majority of the carriers become delocalized at RT. Furthermore, the temperature dependent PL also shows an S‐shape behavior, which is a signature of localization effects. A theoretical model, which was derived by solving a rate equation was employed. The model successfully reproduces the observed S‐shape behavior and the theory fits well with the experimental data. The RT band gap of GaAs1−xBix for x up to 0.108 has been plotted and compared with the literature.

This paper reports a simple technique to grow high-yield gold nanoplates directly on the surface via an effective two-dimensional growth promotion of the attached nanoseeds in the presence of a binary surfactant mixture, namely, poly(vinylpyrrolidone) (PVP) and cetyltrimethylammonium bromide (CTAB). The gold nanoplates formation strongly depended on the concentration of PVP used in the solution, while the nanoplate size depended on the CTAB concentration. In a typical process with optimum PVP and CTAB concentrations, 60% of the nanocrystal product was nanoplates. Triangular nanoplates were found to be the major shape of the nanoplates with a yield of up to ca. 50%, while hexagonal or truncated-hexagonal and rounded-nanoplates shared up to ca. 30 and 20% of the nanoplates product, respectively. The nanoplates were characterized by a very thin structure with a thickness of less than 10 nm. The edge-length size of the nanoplates was found to be up to ca. 1 µm. At optimum growth conditions, ca. 70% of the surface area was covered by nanoplates. X-ray diffraction results on the surface modified nanoplates samples indicated exceedingly high Au(111) peaks of gold nanocrystal without the presence of other peaks, such as ( 200) and ( 220), in the diffraction spectrum. The present approach may be used to produce a surface that contains unique nanostructured Au(111) crystallographic plane characteristics, which should find potential applications in catalysis, surface-enhanced Raman scattering, sensors and photonics.

This review collates around 100 papers that developed micro-electro-mechanical system (MEMS) capacitive microphones. As far as we know, this is the first comprehensive archive from academia on this versatile device from 1989 to 2019. These works are tabulated in term of intended application, fabrication method, material, dimension, and performances. This is followed by discussions on diaphragm, backplate and chamber, and performance parameters. This review is beneficial for those who are interested with the evolutions of this acoustic sensor.

The recent advancement of dielectrophoresis (DEP)-enabled microfluidic platforms is opening new opportunities for potential use in cancer disease diagnostics. DEP is advantageous because of its specificity, low cost, small sample volume requirement, and tuneable property for microfluidic platforms. These intrinsic advantages have made it especially suitable for developing microfluidic cancer diagnostic platforms. This review focuses on a comprehensive analysis of the recent developments of DEP enabled microfluidic platforms sorted according to the target cancer cell. Each study is critically analyzed, and the features of each platform, the performance, added functionality for clinical use, and the types of samples, used are discussed. We address the novelty of the techniques, strategies, and design configuration used in improving on existing technologies or previous studies. A summary of comparing the developmental extent of each study is made, and we conclude with a treatment of future trends and a brief summary.