Crystal Phase- and Orientation-Dependent Electrical Transport Properties of InAs Nanowires.
Crystal Phase- and Orientation-Dependent Electrical Transport Properties of InAs Nanowires.
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DOI：
10.1021/acs.nanolett.6b00045
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发表时间：
2016-03
期刊：
影响因子：
10.8
通讯作者：
M. Fu;Z. Tang;Xing Li;Z. Ning;D. Pan;Jianhua Zhao;Xianlong Wei;Qing Chen
中科院分区：
文献类型：
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作者：
M. Fu;Z. Tang;Xing Li;Z. Ning;D. Pan;Jianhua Zhao;Xianlong Wei;Qing Chen
本文系统地研究了分子束外延生长的单晶InAs纳米线的电输运特性与晶相和取向的关系。开发了一种新方法，允许将相同的InAs NW用于电气测量和透射电子显微镜表征。我们发现，晶体相位、纤锌矿（WZ）或锌-闪锌矿（ZB）以及InAs NWs的取向都显著影响基于这些NWs的场效应晶体管的电子特性，如阈值电压（VT）、通断比、亚阈值摆幅（SS）和关闭状态下的有效势垒高度（ΦOFF）。SS增加，而VT，开关比和ΦOFF在WZ⟨0001⟩，ZB⟨131⟩，ZB⟨332⟩，ZB⟨121⟩和ZB⟨011⟩的序列中依次减少。在VBG = 0 V时，WZ InAs NWs的场效应迁移率、电导率和电子浓度明显小于ZB InAs NWs，而这些参数对ZB InAs NWs的取向不敏感。我们还发现直径在12 ~ 33 nm范围内对InAs NWs电输运性质的影响远小于晶相和取向。通过温度相关测量，无论晶体相和取向的变化如何，InAs NWs与金属之间的良好欧姆接触仍然存在。我们的工作加深了对InAs NWs的结构依赖的电输运性质的理解，并提供了一种通过控制NWs的晶相和取向来定制器件性质的潜在方法。
We report a systematic study on the correlation of the electrical transport properties with the crystal phase and orientation of single-crystal InAs nanowires (NWs) grown by molecular-beam epitaxy. A new method is developed to allow the same InAs NW to be used for both the electrical measurements and transmission electron microscopy characterization. We find both the crystal phase, wurtzite (WZ) or zinc-blende (ZB), and the orientation of the InAs NWs remarkably affect the electronic properties of the field-effect transistors based on these NWs, such as the threshold voltage (VT), ON-OFF ratio, subthreshold swing (SS) and effective barrier height at the off-state (ΦOFF). The SS increases while VT, ON-OFF ratio, and ΦOFF decrease one by one in the sequence of WZ ⟨0001⟩, ZB ⟨131⟩, ZB ⟨332⟩, ZB ⟨121⟩, and ZB ⟨011⟩. The WZ InAs NWs have obvious smaller field-effect mobility, conductivities, and electron concentration at VBG = 0 V than the ZB InAs NWs, while these parameters are not sensitive to the orientation of the ZB InAs NWs. We also find the diameter ranging from 12 to 33 nm shows much less effect than the crystal phase and orientation on the electrical transport properties of the InAs NWs. The good ohmic contact between InAs NWs and metal remains regardless of the variation of the crystal phase and orientation through temperature-dependent measurements. Our work deepens the understanding of the structure-dependent electrical transport properties of InAs NWs and provides a potential way to tailor the device properties by controlling the crystal phase and orientation of the NWs.