Single and multiple doping effects on electron transport in zigzag silicene nanoribbons

TL;DR

This study uses advanced computational methods to analyze how doping zigzag silicene nanoribbons with Al or P atoms affects their electronic and spin transport properties, revealing position-dependent acceptor-donor behavior and impurity interactions.

Contribution

It provides detailed insights into the effects of single and multiple dopants on the electronic and spin transport in zigzag silicene nanoribbons, highlighting position-dependent doping behavior.

Findings

Single dopants create quasibound states affecting conductance.

Dopant position determines acceptor or donor behavior.

Impurity interactions modify conductance in multi-doped ribbons.

Abstract

A nonequilibrium Green's function technique combined with density functional theory is used to study the spin-dependent electronic band structure and transport properties of zigzag silicene nanoribbons (ZSiNRs) doped with aluminum (Al) or phosphorus (P) atoms. The presence of a single Al or P atom induces quasibound states in ZSiNRs that can be observed as new dips in the electron conductance. The Al atom acts as an acceptor whereas the P atom acts as a donor when it is placed at the center of the ribbon. This behavior is reversed when the dopant is placed on the edges. Accordingly, an acceptor-donor transition is observed in ZSiNRs upon changing the dopant's position. Similar results are obtained when two silicon atoms are replaced by two impurities (Al or P atoms) but the conductance is generally modified due to the impurity-impurity interaction. When the doping breaks the two-fold rotational symmetry about the central line, the transport becomes spin dependent.