Dual-mode operation of 2D material-base hot electron transistors.

Yann-Wen Lan,Kang L Wang,Lain-Jong Li,Hussam Qasem,Carlos M Torres,,Mitchell B Lerner,Shin-Hung Tsai,Yumeng Shi,Wen-Kuan Yeh,James R Adleman,Xiaodan Zhu

doi:10.1038/srep32503

Abstract

Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS2, in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (VCB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS2 in the base region) with the application of a negative collector-base potential (VCB < 0). That is, our 2D material-base hot electron transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of VCB. Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying VCB. We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications.

Highlights

We have demonstrated a novel vertical dual-mode 2D material-base hot-electron transistor (2D-HET) incorporating either monolayer MoS2 (MoS2-HET) or monolayer graphene (G-HET) in the base region. This new class of 2D-HETs can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular bias configuration
For the hot-electron dominating mode of operation (VCB > 0), once the hot-electrons tunneling through the emitter-base tunnel barrier have sufficient kinetic energy, they can vertically transport through the 2D material base region, surpass the filter barrier at the collector-base junction, and reach the collector
For the reverse base-collector current dominating mode of operation (VCB < 0), the continuously increasing filter barrier precludes the injected hot-electrons from having sufficient kinetic energy to reach the collector, they back-scatter into the 2D material base region

Summary

Introduction

We have demonstrated a novel vertical dual-mode 2D material-base hot-electron transistor (2D-HET) incorporating either monolayer MoS2 (MoS2-HET) or monolayer graphene (G-HET) in the base region. This new class of 2D-HETs can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular bias configuration.

Results

Conclusion