Electrical Properties of Exfoliated Multilayer Germanium Selenide (GeSe) Nanoflake Field-Effect Transistors

Abstract

We report on the electrical properties of natural p-type GeSe nanoflakes, which were mechanically exfoliated from GeSe single crystals by the polydimethylsiloxane (PDMS) stamp method, using a back-gate field effect transistor (FET) measured in a vacuum probe station at room temperature. In this study, we used two contact metals, including Au and Cr metals, as the Ohmic contacts to the GeSe nanoflake FETs, resulting in an Ohmic behavior with the Au contacts, with a total resistance of 5.5 x 10(6) Omega. We also found that the 40-nm-thick GeSe nanoflake FET exhibits clear p-type semiconductor behavior with a field-effect mobility of similar to 1.0 x 10(-3) cm(2)/(V.s) and a current on/off ratio of similar to 10(4) at room temperature.