DFT insights into the selective NH 3 sensing mechanism of two dimensional ZnTe monolayer.

Exploring novel NH 3 sensing materials is crucial in chemical industries, fertilizing plants and medical fields. Herein, for the first time, the NH 3 sensing behaviors and sensing mechanisms of two dimensional (2D) ZnTe monolayer are systematically investigated by density functional theory calculations. It is shown that 2D ZnTe monolayer exhibits excellent selective NH 3 sensing properties. (220) crystal facet of ZnTe possesses a higher NH 3 adsorption energy (-1.59 eV) and a larger charge transfer (0.195e) than (111) and (311) crystal facets. The positive charges could enhance NH 3 sensing while the negative charges could reduce NH 3 sensing. The NH 3 adsorption strengths are significantly improved in O 2 atmosphere while it is negligibly affected by N 2 atmosphere and H 2 O atmosphere. Moreover, the presence of Zn vacancy and Fe, Co, Ni doping could improve the NH 3 sensing of ZnTe. Additionally, the experimental results confirms that ZnTe possesses a low detection limit of 0.1 ppm NH 3 . These theoretical predictions and experimental results present a wide range of possibilities for the further development of ZnTe monolayer in NH 3 sensing fields.