Fabrication and Characterization of High-Mobility Graphene p–n–p Junctions Encapsulated by Hexagonal Boron Nitride

Abstract

We report on the fabrication and characterization of high quality graphene p–n–p junctions encapsulated by hexagonal boron nitride. By tuning the back gate and top gate bias voltages, a graphene p–n–p junction with tunable polarity and doping levels was realized. The p–n–p junction displayed distinct resistance oscillations, which was attributed to the Fabry–Perot interference of charge carriers in the p–n–p cavity. When a small magnetic field was applied, the oscillation phase was shifted by π, indicating the observation of Klein tunneling of charge carriers in the p–n–p junctions. The observation of Fabry–Perot interference and Klein tunneling with a macroscopic cavity length of Lc = 500 nm demonstrates the markedly high quality of our graphene p–n–p junction.