Dresden 2017 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 27: 2D Materials beyond Graphene (jointly with O)
DS 27.4: Poster
Dienstag, 21. März 2017, 18:30–20:30, P2-EG
Thermodynamic stability, electronic and optical properties of graphene oxide dependence on oxidation level. — •Ivan Guilhon1, Lara K Teles1, Marcelo Marques1, Friedhelm Bechstedt2, Jürgen Fürthmuller2, and Silvana Botti2 — 1Grupo de Materiais Semicondutores e Nanotecnologia, Instituto Tecnológico de Aeronáutica, DCTA, 12228-900 São José dos Campos, Brazil — 2Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, D-07743 Jena, Germany
Graphene oxide is a two-dimensional material with potential applications in ultra-thin electronic, optoelectronic and sensor devices. It is an intermediate compound in the graphene synthesis through chemical route. Despite the fact that the chemical composition of such system have strong influence on its electronic and optical process, these interesting features have not been investigated until now.
We propose a statistical model for graphene oxide based on the cluster expansion of the disordered system based on the generalized quasi-chemical approximation (GQCA). Epoxide and hydroxyl groups are considered. Thermodynamic stability of the system is investigated and the known tendency of the system to decompose into highly oxidized domains and pristine graphene is explained and discussed in the light of binodal and spinodal decomposition. We calculate the energy gap as a function of the degree of oxidation considering composition fluctuation effects in the whole composition range, showing tunable electronic properties in a wide range interval. Optical absorbance spectra are predicted for different chemical compositions.