Versatile Sensing Structure: GaP/Au/Graphene/Silicon

A versatile sensing scheme for gas and biomolecule detection has been proposed theoretically using optimized GaP/Au/Graphene/Silicon structures. A Gallium Phosphide (GaP) prism is used as a substrate in the proposed surface plasmon resonance based sensing scheme, which is designed to be in Kretschmann configuration. The thicknesses of different constituent layers have been optimized for the maximum values of the sensitivities of the gas and bio-sensing probes. To delineate the role of the silicon layer, sensing probes without a silicon layer have also been numerically modelled and compared. The present GaP/Au/Graphene/Silicon probes possess higher values of sensitivity for the detection of gas and biomolecules compared to the conventional SPR sensing probes reported in the literature.

Modelling of voltage changes in the n-p junction in the pulse mode

The article presents the results of modeling the effect of the effective lifetime in the space charge region (SCR) of the n+-p junction on the impulse characteristics of silicon structures. The model is based on solving the fundamental system of differential equations for the transport of charge carriers in inhomogeneous semiconductors. The calculated time dependences of the voltage change in the SCR for a pulse voltage change on the n+-p-p+ structure correspond to the experimental data.

Creation of bilateral structures of macroporous silicon with nanocoatings for solar cells

We have proposed a new technological solution for the creation of solar energy elements using bilateral structures of macroporous silicon to increase the overall efficiency of converting light energy into electricity. Recently, the research on R&D in solar cell technology has focused mainly on crystalline silicon technologies and photovoltaic systems, including organic ones. The main physical phenomenon that determines the prospects of two-dimensional structures of macroporous silicon with nanocoatings as solar cells is the increase in absorption of electromagnetic radiation and photoconductivity as a result of interaction of optical modes with the developed surface of cylindrical macropores with a barrier on the nanocoating-surface boundary. We fabricated two-sided macroporous silicon structures with nanocoatings for solar cells, including silicon technology, organic nanoformations, and photovoltaic system formation. Silicon is a promising material for the manufacture of structures with a cylindrical geometry of air macropores due to the anisotropy of the cheap process of photoelectrochemical etching. The presence of periodically located cylindrical pores separated by silicon columns provides a large effective surface of the samples and enhanced optical and photophysical characteristics of silicon structures. Polymer composites with nanocoatings with CdS nanocrystals and multilayer carbon nanotubes in polyethyleneimine generate charges of opposite sign on both surfaces of the structures under illumination. The formation of bilateral structures of macroporous silicon with nanocoatings increases the overall energy conversion efficiency in solar cells by up to 60 %. In addition, one can use our proposed solar cells in the upper atmosphere.