Due to the edge states of zigzag graphene nanoribbon (ZGNR), heterojunctions of p- and n-type doped ZGNRs with either high rectification ratios or high spin-filter efficiencies are constructed. Four ZGNR-based heterojunctions are designed theoretically by replacing the edge carbon atoms of two ZGNR electrodes with boron atoms and nitrogen atoms, respectively. The electron-transport properties and the spin-transport properties are studied by applying non-equilibrium Green's function method combined with first principles calculations. The numerical results show that, such heterojunctions show 100% spin-filter efficiencies in the lower negative bias regime. This excellent spin-filter behavior originates from the localized spin-up sub-bands that lie on the Fermi level of boron-doped electrode and lead to a destructive interference of electrons in the scattering region, thereby preventing the spin-up electrons from entering the electrode and leading to a near-zero spin-up current in lower bias regime. When the dopant boron and nitrogen atoms are hydrogenated, the 100% spin-filter efficiency disappears, but the rectification ratio up to 10⁶ is obtained. This amazing rectification ratio results from the vanishing overlap of conduction bands of the two electrodes for both spin-up and spin-down sub-bands when the absolute value of the negative bias is greater than 0.4 V.

由于之字形石墨烯纳米带（ZGNR）的边缘状态，构造了具有高整流比或高自旋滤光效率的p型和n型掺杂ZGNR的异质结。理论上，通过分别用硼原子和氮原子替换两个ZGNR电极的边缘碳原子来设计四个基于ZGNR的异质结。通过应用非平衡格林函数方法结合第一性原理计算研究了电子的传输性质和自旋传输性质。数值结果表明，这种异质结在较低的负偏置状态下显示100％的自旋滤波器效率。这种出色的自旋滤波器性能源自位于掺硼电极费米能级上的局部自旋向上子带，并导致电子在散射区域发生破坏性干涉，从而防止了自旋向上电子进入电子。电极，并在较低偏置状态下导致接近零的旋转电流。当掺杂剂硼和氮原子氢化时，100％的自旋过滤器效率消失，但精馏比高达10获得⁶。当负偏压的绝对值大于0.4 V时，对于自旋向上和自旋向下子带，两个电极的导带消失的重叠导致了这种惊人的整流比。