Synthesis, Characterization and Fabrication of Graphene/Boron Nitride Nanosheets Heterostructure Tunneling Devices.

Muhammad Sajjad,Muhammad S Sultan,Gerardo Morell,Peter X Feng,Vladimir Makarov,Wojciech M Jadwisienczak,Frank Mendoza,Brad R Weiner,Ali Aldalbahi

doi:10.3390/nano9070925

Abstract

Various types of 2D/2D prototype devices based on graphene (G) and boron nitride nanosheets (BNNS) were fabricated to study the charge tunneling phenomenon pertinent to vertical transistors for digital and high frequency electronics. Specifically, G/BNNS/metal, G/SiO2, and G/BNNS/SiO2 heterostructures were investigated under direct current (DC-bias) conditions at room temperature. Bilayer graphene and BNNS were grown separately and transferred subsequently onto the substrates to fabricate 2D device architectures. High-resolution transmission electron microscopy confirmed the bilayer graphene structure and few layer BNNS sheets having a hexagonal B3-N3 lattice. The current vs voltage I(V) data for the G/BNNS/Metal devices show Schottky barrier characteristics with very low forward voltage drop, Fowler-Nordheim behavior, and 10−4 Ω/sq. sheet resistance. This result is ascribed to the combination of fast electron transport within graphene grains and out-of-plane tunneling in BNNS that circumvents grain boundary resistance. A theoretical model based on electron tunneling is used to qualitatively describe the behavior of the 2D G/BNNS/metal devices.

Highlights

Graphene [1] and other atomically thin layered materials [2,3] have opened up new possibilities for fabricating compact 2-dimensional (2D) nanomaterial heterostructures with novel electronic and optoelectronic properties
There is a promise for 2D layered materials to yield new device heterostructures that can work in low power and high frequency electronics without significant change in input characteristics
The out-of-plane electron tunneling through atomically thin layers of boron nitride nanosheets (BNNS) makes this material advantageous for 2D/2D heterostructure devices where BNNS can be used as gate-controlled p-layer [13]

Summary

Introduction

Graphene [1] and other atomically thin layered materials [2,3] have opened up new possibilities for fabricating compact 2-dimensional (2D) nanomaterial heterostructures with novel electronic and optoelectronic properties. Stacking graphene on boron nitride nanosheets (BNNS) is one example [4] of such 2D/2D device structures useful for vertical transistors in digital and high frequency electronics [5].

Results

Conclusion