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The well-known effect of the local interaction between graphene and photoresist (LIGF) during the creation of biosensors is shown to lead to non-uniform distribution of compressive stresses, which deteriorates the adsorption properties of graphene, parameter reproducibility, and detecting ability of influenza B and SARS-Cov-2 biosensors. It is also shown that controlling the occurrence of LIGF areas on a graphene surface by atomic force microscopy or introducing a protective layer between graphene and photoresist can minimize the non-persistent effect of LIGF. The results of influenza B and SARS-CoV-2 imaging on the graphene surface in biosensor chips in a scanning electron microscope are presented. [ABSTRACT FROM AUTHOR]

We report on the molecular beam epitaxy growth of Au-assisted GaAs p-type-doped NW arrays on the n-type GaAs(111)B substrate and their photovoltaic properties. The samples are grown at different substrate temperature within the range from 520 to 580 °C. It is shown that the dependence of conversion efficiency on the substrate temperature has a maximum at the substrate temperature of 550 °C. For the best sample, the conversion efficiency of 1.65% and the fill factor of 25% are obtained. [ABSTRACT FROM AUTHOR]

Under study are temperature dependences of laser characteristics of a GaAs/(AlGa)xOy microdisk of 6 μm in diameter, fabricated using optical lithography, ion milling with a beam of Ar+ ions, and selective oxidation of the Al0.97Ga0.03As layer which forms the microdisk base. In As/InGaAs QDs are used as the microdisk active region. Room-temperature lasing in the 1.3-μm range is observed, with the threshold optical pumping power of 160 μW. The quality factor of microdisk modes is about 104. [ABSTRACT FROM AUTHOR]

The technology of fabricating photonic crystals with the use of nanoimprint lithography is described. One- and two-dimensional photonic crystals are produced by direct extrusion of polymethyl methacrylate by Si moulds obtained via interference lithography and reactive ion etching. The period of 2D photonic crystals, which present a square array of holes, ranges from 270 to 700 nm; the aperture diameter amounts to the half-period of the structure. The holes are round-shaped with even edges. One-dimensional GaAs-based photonic crystals are fabricated by reactive ion etching of GaAs to a depth of 1 μm through a mask formed using nanoimprint lithography. The resulting crystals have a period of 800 nm, a ridge width of 200 nm, and smooth nearly vertical side walls. © 2005 Pleiades Publishing, Inc. [ABSTRACT FROM AUTHOR]