Electrical and Optical Characterization of Surface Passivation in GaAs Nanowires
Electrical and Optical Characterization of Surface Passivation in GaAs Nanowires
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DOI：
10.1021/nl301391h
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发表时间：
2012-09-01
期刊：
影响因子：
10.8
通讯作者：
Cronin, Stephen B.
中科院分区：
文献类型：
--
作者：
Chang, Chia-Chi;Chi, Chun-Yung;Cronin, Stephen B.
我们报告了 AlxGa1-xAs 钝化 GaAs 纳米线中载流子动力学的系统研究。通过钝化，少数载流子扩散长度 (L-diff) 从 30 nm 增加到 180 nm（通过电子束感应电流 (EBIC) 映射测量），并且光致发光 (PL) 寿命从低于 60 ps 增加到 1.3 ns。在有和没有 AlxGa1-xAs 钝化层的同一纳米线上观察到连续波 PL 强度增强了 48 倍，表明表面复合显着减少。这些结果表明，在钝化纳米线中，少数载流子寿命不受孪生堆垛层错的限制。根据PL寿命和少数载流子扩散长度，我们估计钝化纳米线的表面复合速度（SRV）范围为1.7 X 10(3)至1.1 X 10(4) cm.s(-1)，少数载流子迁移率mu估计在10.3至67.5 cm(2) V-1 s(-1)范围内。
We report a systematic study of carrier dynamics in AlxGa1-xAs-passivated GaAs nanowires. With passivation, the minority carrier diffusion length (L-diff) increases from 30 to 180 nm, as measured by electron beam induced current (EBIC) mapping, and the photoluminescence (PL) lifetime increases from sub-60 ps to 1.3 ns. A 48-fold enhancement in the continuous-wave PL intensity is observed on the same individual nanowire with and without the AlxGa1-xAs passivation layer, indicating a significant reduction in surface recombination. These results indicate that, in passivated nanowires, the minority carrier lifetime is not limited by twin stacking faults. From the PL lifetime and minority carrier diffusion length, we estimate the surface recombination velocity (SRV) to range from 1.7 X 10(3) to 1.1 X 10(4) cm.s(-1), and the minority carrier mobility mu is estimated to lie in the range from 10.3 to 67.5 cm(2) V-1 s(-1) for the passivated nanowires.