▎ 摘　　要

Spin-polarized electron transport through the zigzag graphene nanoribbon (ZGNR) is investigated by assuming that it couples with different charomium triiodide (CrI3) geometries, respectively. That is to say that the ZGNR either absorbs the monolayer CrI3 or one CrI3 molecule, or couples laterally with one CrI3 molecule. It is found that the spin polarization in the electron transport process is tightly dependent on the CrI3 geometry and the ZGNR-CrI3 coupling manner. When the CrI3 molecule is absorbed on the surface of the ZGNR, the spin-polarization efficiency is much higher than the other two cases, accompanied by the wide spin-polarization region. This work provides a new kind of scheme for optimizing the spin polarization in graphene-based materials.