Approaching the Collection Limit in Hot Electron Transistors with Ambipolar Hot Carrier Transport

Wei Liu; Lingfei Li; Hongwei Guo; Akeel Qadir; Srikrishna Chanakya Bodepudi; Khurram Shehzad; Whenchao Chen; Ya-Hong Xie; Xiaomu Wang; Bin Yu; Yang Xu

doi:10.1021/acsnano.9b07020

Approaching the Collection Limit in Hot Electron Transistors with Ambipolar Hot Carrier Transport

ACS Nano. 2019 Dec 24;13(12):14191-14197. doi: 10.1021/acsnano.9b07020. Epub 2019 Nov 26.

Authors

Wei Liu¹, Lingfei Li¹, Hongwei Guo¹, Akeel Qadir¹, Srikrishna Chanakya Bodepudi¹, Khurram Shehzad¹, Whenchao Chen^{1

2}, Ya-Hong Xie³, Xiaomu Wang⁴, Bin Yu¹, Yang Xu^{1

2}

Affiliations

¹ College of Information Science and Electronic Engineering, College of Microelectronics, Zhejiang Key Laboratory for Advanced Microelectronic Intelligent Systems and Applications, ZJU Micro-Nano Fabrication Center , Zhejiang University , Hangzhou 310027 , China.
² Zhejiang University/University of Illinois at Urbana-Champaign Institute , Haining 314400 , China.
³ Department of Materials Science and Engineering , University of California , Los Angeles , California 90095 , United States.
⁴ National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructure , Nanjing University , Nanjing 210093 , China.

PMID: 31755701
DOI: 10.1021/acsnano.9b07020

Abstract

Hot electron transistors (HETs) containing two-dimensional (2D) materials promise great potential in high-frequency analog and digital applications. Here, we experimentally demonstrate all-2D van der Waals (vdW) HETs formed by graphene, hBN, and WSe₂, in which the polarity of carriers could be tuned by changing bias conditions. We proposed a theoretical model to distinguish hot hole and hot electron components in the ambipolar vdW HET. Importantly, both hot hole and hot electron modes are achieved with pronounced saturation behavior as well as record-high collection efficiency approaching theoretical limits (99.9%) at room temperature. The vdW HETs show a maximum output current density of 400 A/cm². The observed ambipolar hot carrier transport with high collection efficiency is promising for high-speed nanoelectronics and 2D hot electron spectroscopy.

Keywords: ambipolar; collection limit; hot carriers; hot electron transistors; two-dimensional materials.