Ultrahigh sensitivity and layer-dependent sensing performance of phosphorene-based gas sensors

Shumao Cui; Haihui Pu; Spencer A Wells; Zhenhai Wen; Shun Mao; Jingbo Chang; Mark C Hersam; Junhong Chen

doi:10.1038/ncomms9632

Ultrahigh sensitivity and layer-dependent sensing performance of phosphorene-based gas sensors

Nat Commun. 2015 Oct 21:6:8632. doi: 10.1038/ncomms9632.

Authors

Shumao Cui¹, Haihui Pu¹, Spencer A Wells^{2

3}, Zhenhai Wen¹, Shun Mao¹, Jingbo Chang¹, Mark C Hersam^{2

3}, Junhong Chen¹

Affiliations

¹ Department of Mechanical Engineering, University of Wisconsin-Milwaukee, 3200 N Cramer Street, Milwaukee, Wisconsin 53211, USA.
² Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA.
³ Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.

Abstract

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).

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.