Space charge limited conduction mechanism in GaAsSb nanowires and the effect of in situ annealing in ultra-high vacuum
Space charge limited conduction mechanism in GaAsSb nanowires and the effect of in situ annealing in ultra-high vacuum
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GaAsSb纳米线空间电荷有限传导机制及超高真空原位退火效应
DOI：
10.1088/1361-6528/ab47aa
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发表时间：
2020
期刊：
影响因子：
3.5
通讯作者：
Iyer, Shanthi
中科院分区：
文献类型：
--
作者：
Parakh, Mehul;Johnson, Sean;Pokharel, Rabin;Ramaswamy, Priyanka;Nalamati, Surya;Li, Jia;Iyer, Shanthi
在这项工作中，首次观察到GaAsSb纳米线（NW）中的空间电荷有限传导机制（SCLC），并研究了超高真空原位退火的效果。 NW 配置中 SCLC 的低起始电压已被有利地利用来提取该材料系统带隙中的陷阱密度和陷阱分布，在整体和单个纳米线中使用简单的温度相关电流-电压测量。超高真空中的原位退火表明，陷阱密度显着降低，从生长的纳米线中的 10 16 cm−3 降至 7× 10 14 cm−3 的低水平，并将更宽的陷阱分布限制在 0.12 eV 的单个陷阱深度。使用导电原子力显微镜 (C-AFM) 对各个单纳米线中的电流传导机制进行比较，进一步证实了 GaAsSb 整体器件中确定的 SCLC 机制是固有的。通过 C-AFM 电流映射观察到更高的电流、增加的 4 K 光致发光 (PL) 强度以及减小的半峰全宽和更对称的 PL 光谱，以及在室温拉曼光谱中增加 TO/LO 模式减少原位退火 NW 的不对称展宽，再次证明了陷阱的有效湮灭，导致 NW 的光学质量与生长的 NW 相比得到了改善。因此，SCLC 机制的 I-V-T 分析已被证明是一种获取 NW 中生长诱导陷阱信息的简单方法。
In this work, the first observation of the space charge limited conduction mechanism (SCLC) in GaAsSb nanowires (NWs) grown by Ga-assisted molecular beam epitaxial technique, and the effect of ultra-high vacuum in situ annealing have been investigated. The low onset voltage of the SCLC in the NW configuration has been advantageously exploited to extract trap density and trap distribution in the bandgap of this material system, using simple temperature dependent current–voltage measurements in both the ensemble and single nanowires. In situ annealing in ultra-high vacuum revealed significant reduction in the trap density from 10 16 cm− 3 in as-grown NWs to a low level of 7× 10 14 cm− 3 and confining wider trap distribution to a single trap depth at 0.12 eV. A comparison of current conduction mechanism in the respective single nanowires using conductive atomic force microscopy (C-AFM) further confirms the SCLC mechanism identified in GaAsSb ensemble device to be intrinsic. Higher current observed in current mapping by C-AFM, increased 4 K photoluminescence (PL) intensity along with reduced full-width half maxima and more symmetric PL spectra, and reduced asymmetrical broadening with increased TO/LO mode in room temperature Raman spectra for in situ annealed NWs again attest to effective annihilation of traps leading to the improved optical quality of NWs compared to as-grown NWs. Hence, the I–V–T analysis of the SCLC mechanism has been demonstrated as a simple approach to obtain information on growth induced traps in the NWs.
III/V 合金中的旋节线分解和团簇
影响因子：
2.1
作者：
G. B. Stringfellow
通讯作者：
G. B. Stringfellow