A steep-slope tellurium transistor with a native voltage amplifying threshold switch

Abstract

What precludes lowering the supply voltage and overall power consumption of the transistor is the infamous Boltzmann tyranny, a fundamental thermionic limit preventing the subthreshold slope (SS) of the transistor from being lower than 60 mV dec−1 at room temperature (RT). Internal voltage amplification through the use of an additional threshold switch (TS) serially connected to the transistor channel has been shown to be highly effective to break the Boltzmann barrier. This approach, however, is typically heterogeneous by employing TS materials that are foreign to the transistor. Recently, semiconducting tellurium (Te) has gained considerable research interest for its use as an emerging low-dimensional p-type channel material with high hole mobility, air-stability, and the ability to be processed at near ambient temperature. In this work, we unveil a hidden advantage of Te for a steep-slope transistor in which Te serves as the channel material and the TS material at the same time. In a homogeneous and compact device architecture, RT-SS lower than 30 mV dec−1 can be achieved. This is enabled by a combination of unique electrical–electrochemical–thermal properties in Te. This work augments the functionality of Te and provides a low-power transistor solution.