Berlin 2015 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 97: Graphene: Structure (jointly with O, HL)

TT 97.7: Vortrag

Donnerstag, 19. März 2015, 12:00–12:15, MA 041

Irradiation of Graphene-FETs with highly charged Ions — •Philipp Ernst¹, Roland Kozubek¹, Oliver Ochedowski¹, Jens Sonntag², Axel Lorke², and Marika Schleberger¹ — ¹Universität Duisburg-Essen, AG Schleberger, Duisburg, Germany — ²Universität Duisburg-Essen, AG Lorke, Duisburg, Germany

We have studied the influence of ion bombardment on the properties of graphene field-effect transistor (FET) structures. We used highly charged ions (HCI) with different potential energies at roughly the same kinetic energy (charge state Xe³²⁺ and Xe²⁵⁺ with E_kin=220 keV and E_kin=195 keV). Electrical transport measurements, Raman spectroscopy, and atomic force microscopy were used to investigate the electrical and structural modifications of the graphene-FETs induced by the ion irradiation. The electrical analysis was performed in-situ in the ultra-high vacuum set up used for the irradiation. For all investigated fluences, the experiments show a reduction of the mobility, which scales with the potential energy of the ions. Remarkably, the influence of the impact of highly charged ions is already measurable at extremly low fluences <15 ions/µ m². As a consequence of the irradiation, a p-doping effect could be observed. Further experiments at lower kinetic energies (<50 keV) are planned to clarify how the potential energy of the impinging HCIs will affect the observed irradiation effects in graphene.