Effect of edge modification on the rectification in graphene ribbons device

We perform first-principles calculations based on density functional theory and non-equilibrium Green's function to investigate the electronic transport properties of the 12-ZGNRs devices with edge modification of OH/NH2, OH/NO2 and OH/SO2. The device with modified edge by OH/SO2 shows the maximum (reverse) rectification ratio of 2076.33(1937.33). We discuss the effect of edge modification on rectifying phenomenon by calculating the transmission spectra and the energy band structures of the related electrodes as well as the PDOS at different bias. And the observed negative differential resistance effect is explained by the transmission spectra for device with modified edge by OH/NH2 and OH/NO2. The results indicate that the edge modification of the OH/SO2 that causes a asymmetric energy band improves the electron transport of the device, suggesting a method to design graphene rectifier with good performance.