Versatile Electronic Devices Based on WSe2/SnSe2 Vertical van der Waals Heterostructure

Van der Waals heterostructures formed by stacking of various two-dimensional materials are promising in electronic applications. However, the performances of most reported electronic devices based on van der Waals heterostructures are far away from existing technologies'. Here we report high performance heterostructure devices based on vertically stacked tungsten diselenide and tin diselenide. Due to the unique band alignment and the atomic thickness of the material, both charge carrier transport and energy barrier can be effectively modulated by the applied electrical field. As a result, the heterostructure devices show superb characteristics, with a high current on-off ratio of around 3 x 108, an average subthreshold slope of 126 mV per decade over five decades of current change due to band to band tunneling, an ultra-high rectification ratio of around 3 x 108 and a current density of more than 104 A per cm2. Further, a small signal half wave rectifier circuit based on majority carrier transport dominated diode is successfully demonstrated, showing great potential in future high speed electronic applications.