Tuning electronic transport properties of zigzag graphene nanoribbons with silicon doping and phosphorus passivation

Vo Trung Phuc,Rajeev Ahuja,Nguyen Thanh Tien

doi:10.1063/1.5035385

Vo Trung Phuc, Rajeev Ahuja + Show 1 more

Open Access

https://doi.org/10.1063/1.5035385

Copy DOI

Journal: AIP Advances	Publication Date: Aug 1, 2018
Citations: 9	License type: cc-by

Affiliation: Can Tho University, Uppsala University

Abstract

Density-functional theory in combination with the non-equilibrium Green’s function formalism is used to study the effect of silicon doping and phosphorus passivation on the electronic transport properties of zigzag graphene nanoribbons (ZGNRs). We study the edge structures passivated by H atoms and by P atoms. In this work, Si atoms are used to substitute C atoms located at the edge of the samples. We consider ZGNRs terminated by H and P atoms with four zigzag carbon chains (4-ZGNRs) in case of six various configurations. Our calculated results determine that the Si doping improves significantly the current of samples by the number of dopants. Moreover, there is dramatical difference in the transmission spectrum of P-passivated ZGNRs and H-passivated ZGNRs i.e. P passivation not only destroys an enhanced transmission at the Fermi level, which is typical for graphene nanoribbons, but also increases considerably the intensity of transmission spectrum with ballistic transport properties. Furthermore, the numerical results illustrate that pristine H-terminated samples have a broadening band gap in transmission spectra when the bias voltage increases. The relationship between the outcomes indicates that such silicon doping and phosphorus passivation are effective and providing a promising way to modulate the properties of ZGNRs for nanoelectronic device applications.

Highlights

Two dimensional (2D) materials have attracted considerable attention because it has exhibited potential applications in optoelectronics devices.[1,2] After the isolation of graphene by Novoselov and coworkers,[3] the novel synthetic routes for graphene have emerged
We investigate the transport property of zigzag graphene nanoribbons (ZGNRs) with edge-chemistry modified by H and P atoms, using the first-principles based on density functional theory (DFT)
We consider six various structures with four zigzag carbon chains. These structures are illustrated in Fig. 1: (a) pristine ZGNR with H passivation (H-ZGNR), (b) Si-doped H-ZGNR (Si-H-ZGNR), (c) 2Si-doped H-ZGNR (2Si-H-ZGNR), (d) pristine ZGNR with P passivation (P-ZGNR), (e) Si-doped P-ZGNR (Si-P-ZGNR) and (f) 2Si-doped P-ZGNR (2Si-P-ZGNR)

Summary

INTRODUCTION

Two dimensional (2D) materials have attracted considerable attention because it has exhibited potential applications in optoelectronics devices.[1,2] After the isolation of graphene by Novoselov and coworkers,[3] the novel synthetic routes for graphene have emerged. Chemical doping is a powerful method to modify the electronic properties of carbon-based nanomaterials, and it could be used to customize the electronic and quantum transport properties of GNRs.[12,13]. . .) are considered for more realistic modeling of GNRs.[18,19] those studies mainly focus on the electronic band structures of the edge chemistry ZGNRs. The transport property with Si substitutional doping and P passivation have not been investigated in details yet, these structures can exist stably.[20]. We investigate the transport property of ZGNRs with edge-chemistry modified by H and P atoms, using the first-principles based on density functional theory (DFT).

SIMULATION MODELS AND CALCULATION METHODS

RESULTS AND DISCUSSION

The effect of passivation atom

The effect of dopant atom

The effect of bias voltage

CONCLUSION