Ultrahigh sensitivity and layer-dependent sensing performance of phosphorene-based gas sensors.
Ultrahigh sensitivity and layer-dependent sensing performance of phosphorene-based gas sensors.
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DOI：
10.1038/ncomms9632
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发表时间：
2015-10-21
影响因子：
16.6
通讯作者：
Chen J
中科院分区：
文献类型：
--
作者：
Cui S;Pu H;Wells SA;Wen Z;Mao S;Chang J;Hersam MC;Chen J
二维（2D）层状材料由于其独特的结构和优异的性能而在器件应用中引起了极大的关注。在这里，场效应晶体管（FET）传感器器件基于2D磷烯纳米片（PNS）制造。PNS传感器对干燥空气中的NO2具有很高的灵敏度，灵敏度与其厚度有关。对于4.8 nm厚的PNS观察到最大响应，在20 ppm（p.p.b.）时灵敏度高达190%。在室温下第一性原理计算结合统计热力学模型预测，当暴露于20 p.p.b.时，4.8 nm厚的PNS的吸附密度为1015 cm−2。NO2在300 K。我们的灵敏度模型进一步表明，灵敏度对PNS厚度的依赖性由较薄片材（<10 nm）的带隙和较厚片材（>10 nm）的气体吸附的有效厚度决定。 磷烯是越来越多的具有高器件应用潜力的2D材料之一。在这里，作者报告了一种由磷烯纳米片组成的传感器，对干燥空气中的NO2表现出高灵敏度，并且还表明灵敏度取决于纳米片厚度。
Two-dimensional (2D) layered materials have attracted significant attention for device applications because of their unique structures and outstanding properties. Here, a field-effect transistor (FET) sensor device is fabricated based on 2D phosphorene nanosheets (PNSs). The PNS sensor exhibits an ultrahigh sensitivity to NO2 in dry air and the sensitivity is dependent on its thickness. A maximum response is observed for 4.8-nm-thick PNS, with a sensitivity up to 190% at 20 parts per billion (p.p.b.) at room temperature. First-principles calculations combined with the statistical thermodynamics modelling predict that the adsorption density is ∼1015 cm−2 for the 4.8-nm-thick PNS when exposed to 20 p.p.b. NO2 at 300 K. Our sensitivity modelling further suggests that the dependence of sensitivity on the PNS thickness is dictated by the band gap for thinner sheets (<10 nm) and by the effective thickness on gas adsorption for thicker sheets (>10 nm). Phosphorene is one of a growing number of 2D materials with high potential for device applications. Here, the authors report a sensor composed of phosphorene nanosheets, showing a high sensitivity to NO2 in dry air and also demonstrate that the sensitivity depends on the nanosheet thickness.