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

Biological and Chemical Physics | Condensed Matter Physics | Physics


This research reports measurements of electron mobility in Graphene Field Effect Transistors (GFET), gated with liquid. Mobility is a quantity describing how easily charge carriers move through a material. GFET biosensors have the greatest sensitivity when the mobility is high; therefore, increasing mobility should improve sensitivity of these and similar devices. An optimal method was established for preparing samples and taking measurements of a liquid-gate device. Sheet conductivity was measured using van der Pauw geometry and carrier density was determined from measurements of the liquid-gate capacitance. It is shown that mobility improves after the graphene surface is cleaned by an annealing process.