CIC nanoGUNE Consolider, 20018 Donostia-San Sebastian Spain.
Nano Lett. 2010 Apr 14;10(4):1387-92. doi: 10.1021/nl100145d.
We report quantitative, noninvasive and nanoscale-resolved mapping of the free-carrier distribution in InP nanowires with doping modulation along the axial and radial directions, by employing infrared near-field nanoscopy. Owing to the technique's capability of subsurface probing, we provide direct experimental evidence that dopants in interior nanowire shells effectively contribute to the local free-carrier concentration. The high sensitivity of s-SNOM also allows us to directly visualize nanoscale variations in the free-carrier concentration of wires as thin as 20 nm, which we attribute to local growth defects. Our results open interesting avenues for studying local conductivity in complex nanowire heterostructures, which could be further enhanced by near-field infrared nanotomography.
我们通过近红外近场纳米光学技术，报道了对轴向和径向掺杂调制的 InP 纳米线中自由载流子分布的定量、非侵入式和纳米分辨率测绘。由于该技术具有亚表面探测能力，我们提供了直接的实验证据，证明了内部纳米线壳中的掺杂剂有效地促进了局部自由载流子浓度。s-SNOM 的高灵敏度还允许我们直接观察到厚度仅为 20nm 的线的自由载流子浓度的纳米级变化，我们将其归因于局部生长缺陷。我们的结果为研究复杂纳米线异质结构中的局部电导率开辟了有趣的途径，通过近场红外纳米断层扫描可以进一步增强这种电导率。
