Electronic and transport properties of zigzag phosphorene nanoribbons with nonmetallic atom terminations

L Sun; Z H Zhang; H Wang; M Li

doi:10.1039/c9ra06360a

Electronic and transport properties of zigzag phosphorene nanoribbons with nonmetallic atom terminations

RSC Adv. 2020 Jan 8;10(3):1400-1409. doi: 10.1039/c9ra06360a. eCollection 2020 Jan 7.

Authors

L Sun^{1

2

3}, Z H Zhang², H Wang³, M Li^{1

4}

Affiliations

¹ School of Physics and Electronics, Central South University Changsha 410083 China.
² School of Physics and Electronic Science, Changsha University of Science and Technology Changsha 410114 China.
³ Guangdong Provincial Key Laboratory of Micro/Nano Optomechatronics Engineering, College of Mechatronics and Control Engineering, Shenzhen University Shenzhen 518060 China whao@szu.edu.cn +86 755 26557471 +86 755 22673522.
⁴ School of Materials Science and Engineering, Georgia Institute of Technology Atlanta Georgia 30332 USA mo.li@gatech.edu +1 404 385 2472.

Abstract

Using the first-principles method based on density-functional theory and nonequilibrium Green's function, electronic properties of zigzag phosphorene nanoribbons (ZPNRs) terminated with nonmetallic (NM) atoms such as H, C, F, N, O, S and Si, as well as a pristine case, are studied systematically. Three possible cases are considered, namely, ZPNRs with symmetrical edge terminations, asymmetrical edge terminations, and the half-bare edge case. It is shown that the pristine ZPNRs show metallic behavior. For ZPNRs terminated with C, O, S and Si atoms, they are always metals regardless of the termination cases. For ZPNR terminated with H, F, and N, the electronic structure is either a metal or a semiconductor, which depends on the termination cases. The results from the calculated edge formation energy show that the ribbons with C, F, N, O, S and Si atom edge modifications are more stable than the H-terminated ZPNR. Moreover, an applied external transverse electric field can effectively modulate the bandgaps of ZPNRs terminated with H, F and N, especially reducing the gap with the increase of the applied external transverse electric field strength. The ZPNRs terminated with N undergo a semiconductor-to-metal transition. We also investigate the electronic transport properties in nano devices consisting of the ZPNRs terminated respectively by O and S at both edges and with the fully bare edge. It is found that O and S terminated ZPNR devices have a good linear response on bias, and the current is bigger than the pristine case. The results indicate that the introduction of NM atoms at the edge(s) can effectively modulate the electronic and transport properties of ZPNRs. These novel electronic properties suggest that PNRs are a promising candidate for future nanoelectronic and optoelectronic applications.