Investigation of Structural, Electronic Properties of Cu-doped twisted bilayer graphene as Oxygen sensor

Twisted Bilayer Graphene (TBLG) is formed when two layers of graphene are twisted at a small angle. In this paper, the electrical structure, adsorption mechanism, density of states (DOS), partial density of states (PDOS), charge transfer process, band structure and TBLG recovery time with and without copper impurities have been investigated to identify oxygen. Changes in Fermi energy, adsorption energy, increase in the area under the DOS confirm the increase in sensory properties of Cu-doped TBLG . The results also showed that Cu-doped TBLG semiconductor acquires conductive properties by adsorbing oxygen. On the other hand, the calculated results for Cu-doped TBLG recovery time show that oxygen adsorption on this structure is more stable compared to TBLG. Accordingly, the Cu-doped TBLG compound for sensor applications at temperatures above room temperature and TBLG at temperatures below room temperature are introduced. The working temperature of the oxygen sensor was 60 K for TBLG with a working time of 28 S and 1600 K for the Cu-doped TBLG with a working time of 118 S.