Analytical expressions for the local densities of states of epitaxial graphene formed on metal and semiconductor substrates are derived on unified grounds. The conditions of strong and weak graphene-s

The adsorption of an atom with a single valence s electron (hydrogen, alkali metals) or with a single valence p-vacancy (halogens) on the surface of a graphene monolayer is considered and the adatom charge is calculated. Cases where the adatom-graphene σ bonds are formed with the participation of p, sp, sp ², and sp ³ states of carbon atoms are analyzed. It is established that the character of hybridization rather weakly influences the charge transfer. The character of adatom charge variation in the series Li → Cs and F → I is analyzed.

The binding energy of atom X (X = B, Al, Ga, In, N, P, As, Sb) substituting for carbon atoms in single-layer graphene, a buffer layer, and on the $\left( {000\bar 1} \right)$ surface of SiC substrate or for a silicon atom on the (0001) surface of SiC substrate has been studied by the Harrison bond-orbital method. In terms of a simple model based on atomic radii, the contribution of the strain energy due to relaxation of an impurity bond has been considered. The expressions have been obtained for the difference between the energies of substitution for a carbon atom in the buffer layer and in single-layer graphene and in the case of substitution for silicon and carbon atoms on the SiC-substrate surface.

A simple model is formulated and used to derive analytical expressions for the density of states in the epitaxial layer of graphene on a metal substrate and the occupation numbers for carbon atoms. Estimations of the charge transfer in this system are obtained for several metal substrates.

This work is devoted to the development and optimization of the parameters of graphene-based sensors. The graphene films used in the present study were grown on semi-insulating 6H-SiC substrates by thermal decomposition of SiC at the temperature of ~1700 °C. The results of measurements by Auger and Raman spectroscopies confirmed the presence of single-layer graphene on the silicon carbide surface. Model approach to the theory of adsorption on epitaxial graphene is presented. It is demonstrated that the Green-function method in conjunction with the simple substrate models permit one to obtain analytical results for the charge transfer between adsorbed molecules and substrate. The sensor structure was formed on the graphene film by laser. Initially, a simpler gas sensor was made. The sensors developed in this study demonstrated sensitivity to the NO₂ concentration at the level of 1–0.01 ppb. The results obtained in the course of development and the results of testing of the graphene-based sensor for detection of protein molecules are also presented. The biosensor was fabricated by the technology previously developed for the gas sensor. The working capacity of the biosensor was tested with an immunochemical system constituted by fluorescein and monoclonal antibodies (mAbs) binding this dye.