Ultrahigh sensitivity and layer-dependent sensing performance of phosphorene-based gas sensors.
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).
Department of Mechanical Engineering, University of Wisconsin-Milwaukee, 3200 N Cramer Street, Milwaukee, Wisconsin 53211, USA.
Shumao
S
Cui
Department of Mechanical Engineering, University of Wisconsin-Milwaukee, 3200 N Cramer Street, Milwaukee, Wisconsin 53211, USA.
Haihui
H
Pu
Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA.|Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
Spencer A
SA
Wells
Department of Mechanical Engineering, University of Wisconsin-Milwaukee, 3200 N Cramer Street, Milwaukee, Wisconsin 53211, USA.
Zhenhai
Z
Wen
Department of Mechanical Engineering, University of Wisconsin-Milwaukee, 3200 N Cramer Street, Milwaukee, Wisconsin 53211, USA.
Shun
S
Mao
Department of Mechanical Engineering, University of Wisconsin-Milwaukee, 3200 N Cramer Street, Milwaukee, Wisconsin 53211, USA.
Jingbo
J
Chang
Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA.|Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
Mark C
MC
Hersam
Department of Mechanical Engineering, University of Wisconsin-Milwaukee, 3200 N Cramer Street, Milwaukee, Wisconsin 53211, USA.
Junhong
J
Chen