InP and InGaAs grown on InP substrate by molecular beam epitaxy

InP and InGaAs epitaxial layers on InP substrates using molecular beam epitaxy (MBE) have been studied. Carrier concentration and mobility of InP and InGaAs are found that are strongly correlated with the growth temperature and V/III ratio. The InGaAs layers using As2 were compared with the layers grown using As4 from a Riber standard cracker cell. When As4 is used, the highest electron mobility of InGaAs is 3960 cm2/(V·s) with the V/III ratio of 65. When converted to As2, the V/III ratio with the highest electron mobility decreased to 20. With the arsenic cracker temperature decreased from 950 ℃ to 830 ℃, the electron mobility increased from 4090 cm2/(V • s) to 5060 cm2/(V • s).

Особенности роста слоев в напряженных сверхрешетках InAs/GaSb

The paper presents the results of a study of factors affecting the thickness of transition (interface) layers in stressed InAs/GaSb superlattices during growth by MOCVD method. It is shown that the thicknesses of the interface layers between InAs and GaSb are practically independent of the growth temperature. The thickness of the interface layers is influenced by the direction of switching the layer growth. The smallest thickness of 1.2-1.4 nm of the interface layer InAs/GaSb was obtained for the direction of growth switching from GaSb to InAs.

The Growth and Morphological Characterization Of Tropical Thermophilic Bacterium Parageobacillus caldoxylosilyticus ER4B

Parageobacillus caldoxylosilyticus is a rod-shaped thermophilic bacterium that can grow optimally at high temperatures. The thermophilicity of the bacterium is expected to be largely accounted for by the production of thermostable enzymes which has valuable applications in many fields. However, the species is poorly studied, hence, the growth conditions at high temperatures remained unclear until today. Therefore, this study aimed to determine the growth characterization of P. caldoxylosilyticus, including growth media preferences, optimal growth temperature, as well as minimum and maximum growth temperature. P. caldoxylosilyticus strain ER4B isolated from oil palm empty fruit bunch compost was used in this study. The bacterial strain was first identified using 16S rRNA sequencing, and the subsequent BLAST result showed that it is closest to P. caldoxylosilyticus strain UTM6. It is found that ER4B grew best in LB as compared to R2A, TSB, and NB medium. Further temperature tests determined the optimum growth temperature of the strain to be at 64°C Besides, the bacterium forms mucoid circular punctiform colonies that are yellowish in color on an agar plate, and the colony is usually 2 mm to 4 mm in diameter. The microscopic analysis also revealed that strain ER4B is a Gram-positive rod-shaped bacterium that has a length ranging from 3 µm to 6 µm, with a diameter of around 0.5 µm.

Scanning probe analysis of twisted graphene grown on a graphene/silicon carbide template

Overlayer growth of graphene on an epitaxial graphene/silicon carbide (SiC) as a solid template by ethanol chemical vapor deposition is performed over a wide growth temperature range from 900 ºC to 1450 ºC. Structural analysis using atomic force and scanning tunneling microscopies reveal that graphene islands grown at 1300 ºC form hexagonal twisted bilayer graphene as a single crystal. When the growth temperature exceeds 1400 ºC, the grown graphene islands show a circular shape. Moreover, moiré patterns with different periods are observed in a single graphene island. This means that the graphene islands grown at high temperature are composed of several graphene domains with different twist angles. From these results, we conclude that graphene overlayer growth on the epitaxial graphene/SiC solid at 1300 ºC effectively synthesizes the twisted few-layer graphene with a high crystallinity.