期刊
NANO LETTERS
卷 16, 期 6, 页码 3426-3433出版社
AMER CHEMICAL SOC
DOI: 10.1021/acs.nanolett.5b03917
关键词
Core-shell wnanowires; III-As semiconductors; surface charges; surface passivation; luminescence
类别
资金
- ANR program JCJC [ANR-12-JS10-0002]
- Agence Nationale de la Recherche (ANR) [ANR-12-JS10-0002] Funding Source: Agence Nationale de la Recherche (ANR)
We present a set of experimental results showing a combination of various effects, that is, surface recombination velocity, surface charge traps, strain, and structural defects, that govern the carrier dynamics of self-catalyzed GaAs/AlGaAs core-shell nano wires (NWs) grown on a Si(111) substrate by molecular beam epitaxy. Time-resolved photoluminescence of NW ensemble and spatially resolved cathodoluminescence of single NWs reveal that emission intensity, decay time, and carrier diffusion length of the GaAs NW core strongly depend on the AlGaAs shell thickness but in a nonmonotonic fashion. Although 7 nm AlGaAs shell can efficiently suppress the surface recombination velocity of the GaAs NW core, the influence of the surface charge traps and the strain between the core and the shell that redshift the luminescence of the GaAs NW core remain observable in the whole range of the shell thickness. In addition, the band bending effect induced by the surface charge traps can alter the scattering of the excess carriers inside the GaAs NW core at the core/shell interface. If the AlGaAs shell thickness is larger than SO nm, the luminescence efficiency of the GaAs NW cores deteriorates, ascribed to defect formation inside the AIGaAs shell evidenced by transmission electron microscopy.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据