Institut d'Electronique, de Microélectronique et de Nanotechnologies (IEMN), CNRS, UMR 8520, Département ISEN, 41 bd Vauban, 59046 Lille Cedex, France.
Sino-European School of Technology, Shanghai University , 99 Shangda Road, Shanghai, 200444, People's Republic of China.
Nano Lett. 2015 Oct 14;15(10):6440-5. doi: 10.1021/acs.nanolett.5b01802. Epub 2015 Sep 9.
The structural and electronic properties of nonstoichiometric low-temperature grown GaAs nanowire shells have been investigated with scanning tunneling microscopy and spectroscopy, pump-probe reflectivity, and cathodoluminescence measurements. The growth of nonstoichiometric GaAs shells is achieved through the formation of As antisite defects, and to a lower extent, after annealing, As precipitates. Because of the high density of atomic steps on the nanowire sidewalls, the Fermi level is pinned midgap, causing the ionization of the subsurface antisites and the formation of depleted regions around the As precipitates. Controlling their incorporation offers a way to obtain unique electronic and optical properties that depart from the ones found in conventional GaAs nanowires.
使用扫描隧道显微镜和光谱学、泵浦探测反射率以及阴极荧光测量，研究了非化学计量低温生长 GaAs 纳米线壳的结构和电子特性。通过形成 As 反位缺陷，并且在退火后以较低的程度形成 As 沉淀，实现了非化学计量 GaAs 壳的生长。由于纳米线侧壁上的原子台阶密度很高，费米能级被钉扎在能隙中间，导致亚表面反位的离化和在 As 沉淀周围形成耗尽区。控制它们的掺入提供了一种获得独特电子和光学性质的方法，这些性质与传统 GaAs 纳米线中发现的性质不同。
