Persistent and reversible electrostatic control of doping in graphene/hexagonal boron nitride heterostructures
Abstract
Since its first application as a substrate for graphene field effect transistors (FETs), hexagonal boron nitride (hBN) has become a prominent component in two-dimensional (2D) material devices. In addition, hBN has been shown to host defects that can be manipulated to change the electronic properties of adjacent 2D materials. Despite the wide use of such defect manipulations, no focused efforts have been made to further the understanding of defect excitations and their influence in graphene/hBN FETs. In this study, we explore the effect of high electric fields (∼10V/nm) on graphene/hBN FETs and find that persistent and reversible shifts in graphene's charge neutrality point (CNP) occur. By increasing the applied electric field and temperature of our device, we find that this CNP shift is enhanced. With this insight, we propose a mechanism that explains these observations based on Poole–Frenkel emissions from defects in hBN. Finally, we show that such an effect may be suppressed by using graphite as a backgate, thus preventing unintended changes in the electrical properties of graphene/hBN FETs.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 22, 2020
- Source ID
- 10.1063/1.5127770
Entities
People
- A. Lara
- A. P. Ramirez
- E. A. Quezada-lopez
- Frédéric Joucken
- Haoze Chen
- J. L. Davenport
- Jairo Velasco
- Kaitlin Hellier
- Kenji Watanabe
- S. Carter
- Takashi Taniguchi
Organizations
- Army Research Office
- Core Research for Evolutional Science and Technology
- National Institute for Materials Science
- National Science Foundation