D. Sen, Y. Zheng, S. Das, S. Ghosh, S. Das
The Pennsylvania State University,
Keywords: graphene, strain engineering, field effect transistor, on/off ratio
Summary:Extraordinarily high carrier mobility in graphene has led to many remarkable discoveries in physics and at the same time invoked great interest in graphene-based electronic devices and sensors. However, the poor on/off current ratio observed in graphene field-effect transistors (GFETs) has stymied its use in many applications. Here, we introduce straintronic GFET (SGFET) with a colossal on/off current ratio in the excess of 107 by exploiting strain-induced reversible nano-crack formation in the source/drain metal contacts with the help of a piezoelectric gate stack. SGFETs also exhibit steep switching with a subthreshold swing (SS) < 1 mV/decade averaged over ~ 6 orders of magnitude change in the source-to-drain current for both electron and hole branch amidst a finite hysteresis window. We also demonstrate high device yield and strain endurance for SGFETs. SGFETs can expand the application space for graphene-based technologies beyond what is currently envisioned.