graphene, hydroxyl group, ab initio calculations, electronic properties, polymorphism, crystal structure, functionalization
Abstract
Density functional theory in the generalized gradient approximation was used to model three new polymorphic varieties of graphene functionalized by the hydroxyl group, consisting only of paired topological defects 4-6-12. Layer modeling was carried out for primitive hexagonal elementary cells with the types of addition of the hydroxyl group T1, T2, T3. Each of the elementary cells contained 36 atoms. As a result of the calculations, it was established that the carbon frame of the initial layer remains stable during functionalization for the T1 and T3 types, while the functionalized layer T2 undergoes destruction. The layer density in hydroxygraphene layers L4-6-12 with attachment types T1 and T3 is 1,34 and 1,36 mg/m2, respectively. This is less than the layer density for similar fluorographene layers by 0,08-0,16 mg/m2. The sublimation energies of stable layers T1 and T3 were 18,16 and 17,37 eV/(COH), respectively. Densities of electronic states and band structures were calculated, in order to determine the band gaps. The value of the band gap width was determined as equal to 3.33 eV for the T1 layer and 1,93 eV for the T3 layer. This enabled the layers thus obtained to be identified as semiconductors.
Author Biographies
Maxim Evgenyevich Belenkov, Chelyabinsk State University, Chelyabinsk
Post-graduate Student, Department of Radiophysics and Electronics
Vladimir Andreevich Greshnyakov, Chelyabinsk State University, Chelyabinsk
Cand. Sc. (Physics and Mathematics), Senior Lecturer of the Condensed Matter Physics Department
Vladimir Mikhailovich Chernov, Chelyabinsk State University, Chelyabinsk
Dr. Sc. (Physics and Mathematics), Associate Professor, Professor of the Radiophysics and Electronics Department
