Bipolar fully spin-polarized photocurrents in zigzag graphene nanoribbons

Abstract

Zigzag graphene nanoribbons (ZGNRs) are highly promising low-dimensional spintronic materials due to their unique magnetic edge structure. However, the generation of a bipolar fully spin-polarized photocurrent through a ZGNR design has rarely been investigated. In this study, we propose a novel approach to achieving the bipolar fully spin-polarized photocurrent in ZGNRs via the linear photogalvanic effects (LPGEs) based on first-principles calculations. By applying a lateral voltage to the ZGNR device, we demonstrate the generation of the LPGE-induced bipolar fully spin-polarized photocurrent. Notably, this photocurrent exhibits 100% spin polarization. Moreover, both the magnitude and direction of the photocurrent can be effectively controlled by varying the applied positive and negative voltages. Furthermore, the bipolar fully spin-polarized characteristics of the photocurrent are independent of the light polarization angle and incident angle. Our research provides new opportunities for designing ZGNRs in graphene-based spintronic logic devices.