Semiconductor devices that rely on quantum tunnelling could be of use in logic, memory and radiofrequency applications. Tunnel devices that exhibit negative differential resistance typically follow an operating principle in which the tunnelling current contributes directly to the drive current. Here, we report a tunnelling field-effect transistor made from a black phosphorus/Al₂O₃/black phosphorus van der Waals heterostructure in which the tunnelling current is in the transverse direction with respect to the drive current. Through an electrostatic effect, this tunnelling current can induce a drastic change in the output current, leading to a tunable negative differential resistance with a peak-to-valley ratio of more than 100 at room temperature. Our device also exhibits abrupt switching, with a body factor (the relative change in gate voltage with respect to that of the surface potential) that is one-tenth of the Boltzmann limit for conventional transistors across a wide temperature range.

依赖量子隧穿的半导体器件可用于逻辑，存储器和射频应用。具有负差分电阻的隧道器件通常遵循一种工作原理，在该原理中，隧道电流直接影响驱动电流。在这里，我们报道了一种由黑磷/ Al ₂ O ₃制成的隧穿场效应晶体管/黑磷范德华结构，其中隧穿电流相对于驱动电流为横向。通过静电效应，该隧穿电流会引起输出电流的急剧变化，从而导致可调的负差分电阻，在室温下其峰谷比大于100。我们的器件还具有突然的开关特性，其体因子（相对于表面电势的栅极电压的相对变化）是常规晶体管在宽温度范围内的玻耳兹曼极限的十分之一。