Quantitatively estimating defects in graphene devices using discharge current analysis method
Quantitatively estimating defects in graphene devices using discharge current analysis method
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DOI：
10.1038/srep04886
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发表时间：
2014-05-08
影响因子：
4.6
通讯作者：
Lee, Byoung Hun
中科院分区：
文献类型：
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作者：
Jung, Ukjin;Lee, Young Gon;Lee, Byoung Hun
石墨烯的缺陷是石墨烯成功应用的首要问题，因为它们对器件性能有很大的影响。然而，一旦石墨烯被集成到器件结构中，石墨烯和周围环境的质量只能使用间接信息来评估，如滞后、迁移率和驱动电流。在这里，我们发展了一种放电电流分析方法，通过分析放电电流来测量场效应晶体管结构中集成的石墨烯的质量，并使用不同的器件结构来检验其有效性。用放电电流分析方法测得影响石墨烯场效应晶体管性能的荷电位密度约为10(14)/cm(2)量级，这与拉曼光谱中D带和G带的强度比密切相关。在聚萘二甲酸乙二酯(PEN)衬底上制备的石墨烯FET的荷电位密度比在SiO_2/Si衬底上的低，这主要是由于石墨烯和PEN之间的界面相互作用减少所致。这种方法可以成为提高使用石墨烯的器件稳定性的不可或缺的手段，因为它提供了一种准确和定量的方法来定义器件制造后的石墨烯质量。
Defects of graphene are the most important concern for the successful applications of graphene since they affect device performance significantly. However, once the graphene is integrated in the device structures, the quality of graphene and surrounding environment could only be assessed using indirect information such as hysteresis, mobility and drive current. Here we develop a discharge current analysis method to measure the quality of graphene integrated in a field effect transistor structure by analyzing the discharge current and examine its validity using various device structures. The density of charging sites affecting the performance of graphene field effect transistor obtained using the discharge current analysis method was on the order of 10(14)/cm(2), which closely correlates with the intensity ratio of the D to G bands in Raman spectroscopy. The graphene FETs fabricated on poly(ethylene naphthalate) (PEN) are found to have a lower density of charging sites than those on SiO2/Si substrate, mainly due to reduced interfacial interaction between the graphene and the PEN. This method can be an indispensable means to improve the stability of devices using a graphene as it provides an accurate and quantitative way to define the quality of graphene after the device fabrication.