Research on the defect types transformation induced by growth temperature of vertical graphene nanosheets
Research on the defect types transformation induced by growth temperature of vertical graphene nanosheets
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垂直石墨烯纳米片生长温度引起的缺陷类型转变研究
DOI：
10.1016/j.jallcom.2018.12.075
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发表时间：
2018
影响因子：
6.2
通讯作者：
Dongyun Wan
中科院分区：
文献类型：
--
作者：
Sixv Zhu;Han Zhang;Jiaou Wang;Binhao Zhao;Dongyun Wan
垂直石墨烯纳米片中缺陷类型的影响因素得到了广泛的研究，但对于在缺陷类型转变中起重要作用的生长温度的系统研究报道较少。本工作采用等离子体增强化学气相沉积(PECVD)方法，在CH4、H_2和Ar气氛中生长了VGNs。通过扫描电子显微镜、拉曼光谱、XPS、NEXAFS和UPS光谱分析发现，随着生长温度的升高，VGNs中的缺陷类型已经明显地从类空位转变为类边界。此外，NEXAFS表明，7.7EV附近的特征是边界状缺陷，以及不间断电源中的 6.7EV附近的特征，这为表征VGNs中的边界状缺陷提供了一个直观的半定量方向。此外，方阻(从1386到175欧姆/平方英尺)和润湿角(从148°到121°)随着温度的升高而减小。结果表明，由于缺陷类型由类空位转变为类边界，改变生长温度是调节VGNs性质的关键，这是一种简单有效的方法。
The influence factors on the defect types in vertical graphene nanosheets (VGNs) are widely researched while few systematic research has been reported on the growth temperature, which should play an important role in the transformation of defects types. In this work, VGNs were grown via plasma enhanced chemical vapor deposition (PECVD) method in the atmosphere of CH4, H2and Ar. Based on SEM, Raman, XPS, NEXAFS and UPS spectrum analysis, we found that the types of defects in VGNs have clearly transformed from vacancy-like to boundary-like, corresponding to the rising growth temperature. Moreover, NEXAFS suggests that features near 7.7 eV are attributed to boundary-like defects, as well as −6.7 eV in UPS, providing an intuitive and half-quantitative direction to characterize boundary-like defects in VGNs. Additionally, the sheet resistance (from 1386 to 175 Ohm/Sq) and the wetting angle (from 148° to 121°) decrease as the temperature rises. It shows that changing the growth temperature, as the easy and effective method, is crucial of modulating the properties of VGNs owning to the transition of defects types from vacancy-like to boundary-like.