Complementary Tunneling Behaviors in van der Waals Vertical Heterostructures

Vertical tunneling transistors are of interest in the development of next-generation electronics. However, due to nonideal metal-semiconductor interfaces, the majority tunneling carrier type and device polarity are largely fixed, posing a key limitation for practical application. The authors demonstrate complementary tunneling behaviors in vertical heterostructures using ultrathin BN as a tunneling barrier and damage-free van der Waals metal as the top contact, in which the majority carrier type can be switched from electrons to holes by a bias voltage. This work provides proof of principle and comprehensive understanding of the tunneling mechanism in these high-performance devices.