Graphene nanomesh as highly sensitive chemiresistor gas sensor.
Graphene nanomesh as highly sensitive chemiresistor gas sensor.
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DOI：
10.1021/ac3012895
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发表时间：
2012-10-02
影响因子：
7.4
通讯作者：
Mulchandani A
中科院分区：
文献类型：
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作者：
Paul RK;Badhulika S;Saucedo NM;Mulchandani A
石墨烯是一种表面全原子的单原子厚碳同素异形体，作为场效应晶体管和化学场效应晶体管传感器的导通通道，具有广阔的应用前景。然而，半金属石墨烯的零带隙仍然限制了其在这些器件中的应用。在这项工作中，乙醇-化学气相沉积（CVD）生长的p型半导体大面积单层石墨烯薄膜通过纳米球光刻和反应离子蚀刻相结合的方式被图图化成纳米网，并被评估为场效应晶体管和化学电阻气体传感器。合成的纳米网的颈宽约为~ 20nm，由反应离子蚀刻过程中形成的聚苯乙烯球之间的间隙组成。根据RIE的持续时间/功率和PS纳米球的大小，可以很容易地控制石墨烯纳米网的颈宽和周期性。制备的GNM晶体管器件具有良好的电子性能，具有高驱动电流和约6的离子/IOFF比，显著高于其薄膜器件。同样，当用作室温下的化学电阻气体传感器时，石墨烯纳米网传感器对NO2和NH3表现出优异的灵敏度，显著高于薄膜传感器。基于乙醇的石墨烯纳米网传感器在NO2和NH3中灵敏度分别为4.32%/ppm和0.71%/ppm，检测限分别为15 ppb和160 ppb。我们在控制纳米网颈宽方面的研究将导致石墨烯基晶体管和传感器的进一步改进。
Graphene is a one atom thick carbon allotrope with all surface atoms that has attracted significant attention as a promising material as the conduction channel of a field-effect transistor and chemical field-effect transistor sensors. However, the zero bandgap of semimetal graphene still limits its application for these devices. In this work, ethanol-chemical vapor deposition (CVD) grown p-type semiconducting large-area monolayer graphene film was patterned into nanomesh by the combination of nanosphere lithography and reactive ion etching and evaluated as field-effect transistor and chemiresistor gas sensors. The resulting neck-width of the synthesized nanomesh was about ~20 nm comprised of the gap between polystyrene spheres that was formed during the reactive ion etching process. The neck-width and the periodicities of the graphene nanomesh could be easily controlled depending the duration/power of RIE and the size of PS nanospheres. The fabricated GNM transistor device exhibited promising electronic properties featuring high drive current and ION/IOFF ratio of about 6, significantly higher than its film counterpart. Similarly, when applied as chemiresistor gas sensor at room temperature, the graphene nanomesh sensor showed excellent sensitivity towards NO2 and NH3, significantly higher than their film counterparts. The ethanol-based graphene nanomesh sensors exhibited sensitivities of about 4.32%/ppm in NO2 and 0.71%/ppm in NH3 with limit of detections of 15 ppb and 160 ppb, respectively. Our demonstrated studies on controlling the neck width of the nanomesh would lead to further improvement of graphene-based transistors and sensors.