Zn-Passivated Zigzag Boron Nitride Nanoribbons for Perfect Spin-Filtering and Negative Differential Resistance Based Devices

The spin polarized structural, electronic, and transport properties of Zn-passivated zigzag boron nitride nanoribbons (ZBNNRs) at the selective boron and nitrogen edge atoms along with H-passivation are investigated. Present density functional theory (DFT) based studies predict that half-metallic property can be obtained in ZBNNRs via selective Zn and H-passivation. The spin active most stable structure of Zn-passivated ZBNNRs is H-BN-Zn irrespective of ribbon width. The current-voltage characteristics of the Zn-passivated ZBNNRs device exhibit the perfect spin-filter characteristics with magnificently high spin-filtering efficiency even under a low bias. Interestingly, the negative differential resistance (NDR) with a large IP/IV (peak-to-valley current ratio (PVCR)) of the order of 103 has also been observed for Zn-BN-H due to spin-up current component. This is because the dangling bonds at the edge atoms break the edge states and stimulates multiple local states, which prevents electron transfer and reduces current to get a better IP/IV ratio. The observed perfect spin-filtering characteristics and NDR effect suggest that Zn-passivated ZBNNRs have immense potentials to be deployed for nanoscale spintronic devices.