Effect of substitutional defects on resonant tunneling diodes based on armchair graphene and boron nitride nanoribbons lateral heterojunctions

Majid Sanaeepur

doi:10.3762/bjnano.11.56

Abstract

A nanometer-scaled resonant tunneling diode based on lateral heterojunctions of armchair graphene and boron nitride nanoribbons, exhibiting negative differential resistance is proposed. Low-bandgap armchair graphene nanoribbons and high-bandgap armchair boron nitride nanoribbons are used to design the well and the barrier region, respectively. The effect of all possible substitutional defects (including BC, NC, CB, and CN) at the interface of graphene and boron nitride nanoribbons on the negative differential resistance behavior of the proposed resonant tunneling diode is investigated. Transport simulations are carried out in the framework of tight-binding Hamiltonians and non-equilibrium Green’s functions. The results show that a single substitutional defect at the interface of armchair graphene and boron nitride nanoribbons can dramatically affect the negative differential resistance behavior depending on its type and location in the structure.

Highlights

Resonant tunneling diodes (RTDs) are among various electronic devices realized on the platform of 2D graphene/hexagonal boron nitride (Gr/hBN) heterostructures [12,13,14,15,16]
The effect of substitutional defects on the NDR behavior of a nanometer-scaled RTD based on 2D heterojunctions of armchair graphene nanoribbons (AGNRs)/ armchair boron nitride nanoribbons (ABNNRs) was investigated
It was shown that a single substitutional defect, depending on its type and position, could severely alter the NDR behavior of the proposed RTD

Summary

Introduction

Resonant tunneling diodes (RTDs) are among various electronic devices realized on the platform of 2D Gr/hBN heterostructures [12,13,14,15,16]. In a RTD, a material with low bandgap energy is sandwiched between two materials with larger bandgaps, i.e., a quantum well between two potential barriers, forming a so-called doublebarrier quantum well structure. Incident electrons with energies equal to the quantized levels of the well pass through the barriers with rather high transmission probabilities. Electrons with other energies have an extremely small chance of passing through. This causes RTDs to exhibit NDR in their current–voltage characteristic

Methods

Results

Conclusion