Sulfur dioxide molecule sensors based on zigzag graphene nanoribbons with and without Cr dopant

• Edge Cr doping is the most favorable configuration in 5-ZGNR.
• AFM coupling is the most stable phase for (SO2+)ZGNR but FM for (SO2+)Cr1-ZGNR.
• Cr doped ZGNR could be potentially used for molecular sensor.

Structure, electronic, and transport properties of sulfur dioxide (SO2) molecule adsorbed on pure and Cr doped zigzag graphene nanoribbons (ZGNRs) are investigated by means of first principle density functional theory and nonequilibrium Greenʼs function computations. It is found that Cr doped ZGNR is more sensitive to SO2 molecule than pure ZGNR. The pure ZGNRs with and without SO2 molecule show similar I–V curves, but the current of Cr doped ZGNR will significant increase after SO2 molecule adsorption.