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 ∼10(15) 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).

中文翻译：

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磷基气体传感器的超高灵敏度和取决于层的传感性能。

二维（2D）分层材料因其独特的结构和出色的性能而在设备应用中引起了极大的关注。在此，基于2D磷光纳米片（PNS）制作了场效应晶体管（FET）传感器器件。PNS传感器对干燥空气中的NO2表现出超高的灵敏度，其灵敏度取决于其厚度。对于4.8 nm厚的PNS，观察到最大响应，在室温下，十亿分之20（ppb）时，灵敏度高达190％。第一性原理计算与统计热力学模型相结合预测，当在300 K下暴露于20 ppb NO2时，4.8 nm厚的PNS的吸附密度为〜10（15）cm（-2）。