Analysis of Vacancy defects in Hybrid Graphene-Boron Nitride Armchair Nanoribbon based n-MOSFET at Ballistic Limit

TL;DR

This paper investigates how vacancy defects in a hybrid Graphene-Boron Nitride nanoribbon affect the performance of an n-MOSFET at the ballistic limit, using DFT and NEGF methods to analyze electronic properties and device behavior.

Contribution

It provides a detailed analysis of vacancy defect impacts on hybrid nanoribbon-based n-MOSFETs, combining DFT and NEGF approaches for the first time in this context.

Findings

Hole vacancies significantly reduce bandgap and effective mass.

ON-current and subthreshold slope increase with vacancy defects.

Device performance is most affected by hole vacancies.

Abstract

Here, we report the performance of vacancy affected supercell of a hybrid Graphene-Boron Nitride embedded armchair nanoribbon (a-GNR-BN) based n-MOSFET at its ballistic transport limit using Non Equilibrium Green's Function (NEGF) methodology. A supercell is made of the 3p configuration of armchair nanoribbon that is doped on the either side with 6 BN atoms and is also H-passivated. The type of vacancies studied are mono (B removal), di (B and N atom removal) and hole (removal of 6 atoms) formed all at the interface of carbon and BN atoms. Density Functional Theory (DFT) is employed to evaluate the material properties of this supercell like bandgap, effective mass and density of states (DOS). Further band gap and effective mass are utilized in self-consistent PoissonSchrodinger calculator formalized using NEGF approach. For all the vacancy defects, material properties show a decrease which is more significant for hole defects. This observation is consistent in the device characteristics as well where ON-current (ION ) and Sub Threshold Slope (SS) shows the maximum increment for hole vacancy and increase is more significant becomes when the number of defects increase.