Department of Physics and IPAP, Yonsei University, Seoul 120-749, Republic of Korea.
Nano Lett. 2010 Jun 9;10(6):2207-10. doi: 10.1021/nl101109p.
We report electronic transport properties of doped Ge-core/Si-shell and Si-core/Ge-shell nanowires (NWs) from first-principles. We obtain single-impurity scattering properties of electrons and holes using density-functional methods for quantum conductance and then estimate charge-carrier mobilities considering multiple impurity scatterings. It is found that holes in the Ge-core/Si-shell NW with B-doped Si and electrons in the Si-core/Ge-shell NW with P-doped Ge have higher mobilities than holes and electrons in other chemical and doping configurations. These results reflect asymmetric radial confinements of charge carriers in the core-shell NWs and show that Si-core/Ge-shell NWs with electron donors in the shell are as promising for nanoelectronic devices as Ge-core/Si-shell NWs with electron acceptors in the shell.
我们从第一性原理报告了掺杂 Ge 核/Si 壳和 Si 核/Ge 壳纳米线（NWs）的电子输运性质。我们使用密度泛函方法获得了电子和空穴的单杂质散射性质，然后考虑多次杂质散射来估计载流子迁移率。结果发现，B 掺杂 Si 的 Ge 核/Si 壳 NW 中的空穴和 P 掺杂 Ge 的 Si 核/Ge 壳 NW 中的电子的迁移率高于其他化学和掺杂配置中的空穴和电子。这些结果反映了载流子在核壳 NW 中的不对称径向限制，并表明壳层中具有电子给体的 Si 核/Ge 壳 NW 在纳米电子器件中与壳层中具有电子受体的 Ge 核/Si 壳 NW 一样有前途。
