Senior Theses

Publication Date


Document Type

Thesis (Open Access)

Degree Name

Bachelor of Science in Physics



Faculty Advisor(s)

Michael Crosser (Thesis Advisor)
Jennifer Heath & Joelle Murray (Committee Members)

Subject Categories

Energy Systems | Engineering Physics | Materials Science and Engineering | Physics | Power and Energy


When operating graphene field effect transistors (GFETs) in fluid, a double layer capacitance (Cdl) is formed at the surface. In the literature, the Cdl is estimated using values obtained using metal electrode experiments. Due to the distinctive electronic and surface properties of graphene, there is reason to believe these estimates are inadequate. This work seeks to directly characterize the double layer capacitance of a GFET. A unique method for determining the Cdl has been implemented, and data has been obtained for three electrolytes and one ionic fluid. The results yield dramatically lower Cdl values than those obtained with metal electrode experiments and also demonstrate significant asymmetry between electron and hole doped behavior in these ambipolar devices.