Faculty Sponsor's Department:
Since the discovery of topological insulators, they have been a hot topic of research in condensed matter physics for their applications in spintronics and, in the long term, robust quantum computing. In particular, Bi2Se3 has been shown to be an excellent topological insulator because of its simple surface states and large energy gap. This project seeks to find best way of measuring the sheet resistance of Bi2Se3 thin films using the Van der Pauw method. The Van der Pauw method consists of measuring the voltage across each of side of a rectangular or square sample, each side having two polarities, then numerically solving for the sheet resistance. Our goal was to find how many of these 8 measurements were necessary to accurately determine the sheet resistance. Bi2Se3 thin films were created using the sputter deposition technique on an MgO (001) substrate. Regular and texture XRD were done on the samples to insure correct microstructure of Bi2Se3. Electrical contacts were then placed on the sample and potential measurements were made across the sample at temperatures ranging from 300K to 20K.