Going Ballistic: Graphene Hot Electron Transistors

TL;DR

This paper reviews the current state of graphene-based hot electron transistors, highlighting their potential for THz operation, experimental demonstrations of basic functionality, and the challenges posed by interface imperfections.

Contribution

It provides a comprehensive overview of the experimental and theoretical advancements in graphene hot electron transistors and discusses the key challenges for future development.

Findings

Potential for THz operation remains promising.

Experimental devices show significant on/off current switching.

Interface imperfections limit device performance and reliability.

Abstract

This paper reviews the experimental and theoretical state of the art in ballistic hot electron transistors that utilize two-dimensional base contacts made from graphene, i.e. graphene base transistors (GBTs). Early performance predictions that indicated potential for THz operation still hold true today, even with improved models that take non-idealities into account. Experimental results clearly demonstrate the basic functionality, with on/off current switching over several orders of magnitude, but further developments are required to exploit the full potential of the GBT device family. In particular, interfaces between graphene and semiconductors or dielectrics are far from perfect and thus limit experimental device integrity, reliability and performance.